UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549


                                   Form 13F

                              FORM 13F COVER PAGE


Report for the Calendar Year or Quarter Ended:  March 31, 2007
                                              -------------------

Check here if Amendment [ ]; Amendment Number:  __________
     This Amendment (Check only one.):          [ ] is a restatement
                                                [ ] adds new holdings entries.

Institutional Investment Manager Filing this Report:

Name:          1st Source Corporation Investment Advisors, Inc.
Address:       P. O. Box 1602
               South Bend, IN  46634

Form 13F File Number:  28-110447
                       ---------

The institutional investment manager filing this report and the person by whom
it is signed hereby represent that the person signing the report is authorized
to submit it, that all information contained herein is true, correct and
complete, and that it is understood that all required items, statements, lists,
and tables, are considered integral parts of this form.

Person Signing this Report on Behalf of Reporting Manager:

Name:     Paul W. Gifford
Title:    Treasurer
Phone:    574.235.2751

Signature, Place, and Date of Signing:

 /s/Paul W. Gifford                South Bend, IN             05/01/07
---------------------          ---------------------         -------------
     [Signature]                   [City, State]                [Date]

Report Type (Check only one):

[X] 13F HOLDINGS REPORT.  (Check here if all holdings of this reporting manager
    are reported in this report.)

[ ] 13F NOTICE.  (Check here if no holdings reported are in this report, and
    all holdings are reported by other reporting manager(s).

[ ] 13F COMBINATION REPORT.  (Check here if a portion of the holdings for this
    reporting manager are reported in this report and a portion are reported by
    other reporting manager(s).)




List of Other Managers Reporting for this Manager:  Not Applicable

FORM 13F SUMMARY PAGE

Report Summary:

Number of Other Included Managers:     None

Form 13F Information Table Entry Total:     147

Form 13F Information Table Value Total:     $200,325
                                            --------

List of Other Included Managers:

Provide a number list of the name(s) and Form 13F file number(s) of all
institutional investment managers with respect to which this report is filed,
other than the manager filing this report.

NONE










Issuer                        Cusip     Value    Shrs or  Sh/  Put/  Invstmt  Other  Voting   Authority
                                       (X$1000)  Prn Amt  Prn  Call  Dscrtn   Mgrs    Sole      Shrd     None

                                                                           

ABBOTT LABS.                002824100     2623     47000             SOLE     NA       47000
AEGON FLOATING PREFERRED    007924509      349     13560             SOLE     NA       13560
AIR PRODUCTS & CHEMICALS    009158106     2217     30000             SOLE     NA       30000
ALCOA, INC.                 013817101     3356     99000             SOLE     NA       99000
ALLIANT TECHSYSTEMS, INC.   018804104     1055     12000             SOLE     NA       12000
ALLSTATE CORP.              020002101     3483     58000             SOLE     NA       58000
AMERICAN ELECTRIC POWER     025537101     1999     41000             SOLE     NA       41000
AMERICAN EXPRESS CO.        025816109      801     14200             SOLE     NA       14200
AMERICAN INTERNATIONAL      026874107      672     10000             SOLE     NA       10000
ANADARKO PETROLEUM CORP.    032511107     2278     53000             SOLE     NA       53000
ANGLO AMERICAN PLC - ADR    03485P102     1876     71000             SOLE     NA       71000
ANHEUSER-BUSCH COMPANIES    035229103      227      4500             SOLE     NA        4500
APACHE CORP.                037411105      841     11900             SOLE     NA       11900
ARCHER DANIELS MIDLAND      039483102     2202     60000             SOLE     NA       60000
ARLINGTON TANKERS LTD.      G04899103      410     17185             SOLE     NA       17185
AT & T INC.                 00206R102     3716     94250             SOLE     NA       94250
AVERY DENNISON CORP.        053611109     1002     15600             SOLE     NA       15600
AVNET, INC.                 053807103     2891     80000             SOLE     NA       80000
AVON PRODUCTS, INC.         054303102     2310     62000             SOLE     NA       62000
BANK OF AMERICA CORP.       060505104      806     15800             SOLE     NA       15800
BANKONE PFD 7.2% 10/15/31   06423W204      473     18600             SOLE     NA       18600
BCE INC.                    05534B760     1273     45000             SOLE     NA       45000
BELO A H CORP.              080555105     1484     79500             SOLE     NA       79500
BIOMET, INC.                090613100     2125     50000             SOLE     NA       50000
BRISTOL MYERS SQUIBB CO.    110122108      861     31000             SOLE     NA       31000
C.R. BARD, INC.             067383109      875     11000             SOLE     NA       11000
CABCO-GS CAP PREFERRED      12679N203     1267     52900             SOLE     NA       52900
CANETIC RESOURCES TRUST     137513107      467     36000             SOLE     NA       36000
CARBO CERAMICS, INC.        140781105     1397     30000             SOLE     NA       30000
CATERPILLAR, INC.           149123101      798     11900             SOLE     NA       11900
CHEVRON CORP.               166764100     1701     23000             SOLE     NA       23000
CHOICEPOINT, INC.           170388102      449     12000             SOLE     NA       12000
CITIGROUP CAPVII PREF       17306N203      481     19000             SOLE     NA       19000
CITIGROUP, INC.             172967101     2577     50200             SOLE     NA       50200
COMPUTER SCIENCES CORP.     205363104     3263     62600             SOLE     NA       62600
CONAGRA FODS, INC.          205887102     2117     85000             SOLE     NA       85000
CONOCOPHILLIPS              20825C104     1217     17800             SOLE     NA       17800
CRESCENT REAL ESTATE        225756105      700     34890             SOLE     NA       34890
DEUTSCHE TELEKOM - ADR      251566105     2182    132000             SOLE     NA      132000
DYNEGY, INC.                26816Q101      241     26000             SOLE     NA       26000
E.I. DU PONT DE NEMOURS     263534109     2323     47000             SOLE     NA       47000
EARTHLINK, INC.             270321102      221     30000             SOLE     NA       30000
EATON VANCE CORP.           278265103      428     12000             SOLE     NA       12000
EDUCATION REALTY TRUST      28140H104      708     47900             SOLE     NA       47900
ELI LILLY & CO.             532457108     1880     35000             SOLE     NA       35000
EMERSON ELECTRIC CO.        291011104     1637     38000             SOLE     NA       38000
ENBRIDGE ENERGY MGMT.       29250X103      860     15924             SOLE     NA       15924
ENCANA CORP.                292505104     2228     44000             SOLE     NA       44000
ENCORE WIRE CORP            292562105      760     30000             SOLE     NA       30000
ENERPLUS RESOURCES          29274D604     1056     25000             SOLE     NA       25000
ESTERLINE TECHNOLOGIES      297425100     2505     61000             SOLE     NA       61000
FEDEX CORP.                 31428X106      827      7700             SOLE     NA        7700
FIRST DATA CORP.            319963104     2044     76000             SOLE     NA       76000
FLUOR CORP. (NEW)           343412102     2064     23000             SOLE     NA       23000
FORTUNE BRANDS, INC.        349631101      638      8100             SOLE     NA        8100
GENERAL ELECTRIC CO.        369604103     2228     63000             SOLE     NA       63000
GEORGIA GULF CORP.          373200203      486     30000             SOLE     NA       30000
GLOBAL PAYMENT, INC.        37940X102      426     12500             SOLE     NA       12500
GLOBALSANTAFE CORP.         G3930E101     1850     30000             SOLE     NA       30000
H & R BLOCK, INC.           093671105      989     47000             SOLE     NA       47000
H.J. HEINZ CO.              423074103     1272     27000             SOLE     NA       27000
HARRIS CORP.                413875105      713     14000             SOLE     NA       14000
HARTFORD FINANCIAL SVC      416515104      583      6100             SOLE     NA        6100
HESS CORP                   42809H107      998     18000             SOLE     NA       18000
HEWLETT-PACKARD CO.         428236103     1846     46000             SOLE     NA       46000
HONEYWELL INTL, INC.        438516106     1842     40000             SOLE     NA       40000
HOSPITALITY PROPERTIES      44106M102     1221     26100             SOLE     NA       26100
HSBC HOLDINGS PLC - ADR     404280406      527      6000             SOLE     NA        6000
HUBBELL, INC. - CLASS B     443510201     1746     36200             SOLE     NA       36200
HUMANA, INC.                444859102     1451     25000             SOLE     NA       25000
HUNTINGTON BANCSHARES INC   446150104      983     45000             SOLE     NA       45000
IDEARC INC                  451663108      709     20200             SOLE     NA       20200
ING GROEP NV PREFERRED      456837202      253     10000             SOLE     NA       10000
INNKEEPERS USA TRUST        4576J0104      977     60000             SOLE     NA       60000
INTEL CORP.                 458140100     2022    105700             SOLE     NA      105700
INTL COAL GROUP, INC.       45928H106      264     50300             SOLE     NA       50300
JOHNSON & JOHNSON           478160104     1687     28000             SOLE     NA       28000
JP MORGAN CHASE CAP PRFD    46623D200      278     11000             SOLE     NA       11000
KEYCORP                     493267108     1424     38000             SOLE     NA       38000
KIMBERLY-CLARK CORP.        494368103     2055     30000             SOLE     NA       30000
LINCOLN NATIONAL CORP.      534187109     1695     25000             SOLE     NA       25000
MARATHON OIL CORP.          565849106     2273     23000             SOLE     NA       23000
MAXIM INTEGRATED PROD.      57772K101      509     17300             SOLE     NA       17300
MCDONALD'S CORP.            580135101      815     18100             SOLE     NA       18100
MCGRAW-HILL COS., INC.      580645109      566      9000             SOLE     NA        9000
MEDTRONIC, INC.             585055106      829     16900             SOLE     NA       16900
MERCK & CO.                 589331107     1369     31000             SOLE     NA       31000
MICROSOFT CORP.             594918104      557     20000             SOLE     NA       20000
MORGAN (J.P.) CHASE & CO.   46625H100     2032     42000             SOLE     NA       42000
MORGAN STANLEY CAP TR II    61747N109      178      7000             SOLE     NA        7000
MOTOROLA, INC.              620076109     2716    153700             SOLE     NA      153700
MYLAN LABS, INC.            628530107     2315    109495             SOLE     NA      109495
NATIONAL FUEL GAS           636180101     2163     50000             SOLE     NA       50000
NEWMONT MINING CORP.        651639106     2578     61400             SOLE     NA       61400
NISOURCE, INC.              65473P105     1711     70000             SOLE     NA       70000
NOKIA CORP. - ADR           654902204      917     40000             SOLE     NA       40000
NORDIC AMERICAN TANKER      G65773106      576     15900             SOLE     NA       15900
NOVARTIS AG - ADR           66987V109     1857     34000             SOLE     NA       34000
OCCIDENTAL PETROLEUM CORP   674599105      888     18000             SOLE     NA       18000
OMNIVISION TECH., INC.      682128103      389     30000             SOLE     NA       30000
ORACLE CORP.                68389X105      725     40000             SOLE     NA       40000
PALL CORP.                  696429307     2664     70100             SOLE     NA       70100
PAR PHARMACEUTICAL          69888P106     1256     50000             SOLE     NA       50000
PARKER-HANNIFIN, CORP.      701094104     1640     19000             SOLE     NA       19000
PENN WEST ENERGY TRUST      707885109      999     34000             SOLE     NA       34000
PEPSICO, INC.               713448108      814     12800             SOLE     NA       12800
PFIZER, INC.                717081103     1642     65000             SOLE     NA       65000
PLAINS ALL AMER PIPELINE    726503105     1008     17500             SOLE     NA       17500
POTASH CORP                 73755L107     1599     10000             SOLE     NA       10000
PRECISION DRILLING TRUST    740215108     2971    130000             SOLE     NA      130000
PROCTER & GAMBLE CO.        742718109      562      8900             SOLE     NA        8900
PROGRESSIVE CORP.           743315103     2182    100000             SOLE     NA      100000
RADIOSHACK CORP.            750438103     1352     50000             SOLE     NA       50000
RAYTHEON CO.                755111507     2518     48000             SOLE     NA       48000
SCHLUMBERGER, LTD.          806857108     1728     25000             SOLE     NA       25000
SERVICEMASTER CO.           81760N109      416     27000             SOLE     NA       27000
SHAW GROUP, INC.            820280105     1876     60000             SOLE     NA       60000
SK TELECOM CO LTD ADR       78440P108      281     12000             SOLE     NA       12000
SONOCO PRODUCTS CO.         835495102     2255     60000             SOLE     NA       60000
SOUTHWEST AIRLINES CO.      844741108     2286    155520             SOLE     NA      155520
SOUTHWEST GAS CORP.         844895102     1784     45900             SOLE     NA       45900
SPRINT NEXTEL CORP          852061100     2844    150000             SOLE     NA      150000
SYMANTEC CORP.              871503108     1799    104000             SOLE     NA      104000
SYMMETRY MEDICAL INC.       871546206      851     52100             SOLE     NA       52100
SYSCO CORP.                 871829107     2199     65000             SOLE     NA       65000
TARGET CORP.                87612E106       59      1000             SOLE     NA        1000
THORNBURG MORTGAGE ASSET    885218107      442     17000             SOLE     NA       17000
TRAVELERS COMPANIES, INC.   89417E109     1553     30000             SOLE     NA       30000
TURKCELL ILETISIM HIZMET    900111204      530     40000             SOLE     NA       40000
TYCO INTERNATIONAL LTD.     902124106      631     20000             SOLE     NA       20000
U.S. BANCORP                902973304     1049     30000             SOLE     NA       30000
UNION PACIFIC CORP.         907818108      102      1000             SOLE     NA        1000
UNITED TECHNOLOGIES CORP    913017109      891     13700             SOLE     NA       13700
USG CORP.                   903293405      373      8000             SOLE     NA        8000
VALERO ENERGY CORP.         91913Y100      709     11000             SOLE     NA       11000
VERIZON COMMUNICATIONS      92343V104     2920     77000             SOLE     NA       77000
VODAFONE GROUP PLC - ADR    92857W209      534     19875             SOLE     NA       19875
W.W. GRAINGER INC.          384802104     1159     15000             SOLE     NA       15000
WADDELL & REED              930059100     1632     70000             SOLE     NA       70000
WAL MART STORES, INC.       931142103     2113     45000             SOLE     NA       45000
WALGREEN CO.                931422109      633     13800             SOLE     NA       13800
WASTE MANAGEMENT, INC.      94106L109     3407     99000             SOLE     NA       99000
WESTERN UNION CO            959802109      801     36500             SOLE     NA       36500
WEYERHAEUSER CO.            962166104      673      9000             SOLE     NA        9000
WILLIAMS COMPANIES, INC.    969457100     1423     50000             SOLE     NA       50000
XTO ENERGY, INC.            98385X106      840     15333             SOLE     NA       15333
ZIMMER HOLDINGS, INC.       98956P102      598      7000             SOLE     NA        7000