<PAGE>

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 
                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D. C. 20549
 
                            ------------------------
 
                                  FORM 10-KSB
 
(Mark One)
 
/X/ ANNUAL REPORT UNDER SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT
    OF 1934 (FEE REQUIRED) FOR THE FISCAL YEAR ENDED DECEMBER 31, 1997
 
/ / TRANSITION REPORT UNDER SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT
    OF 1934 (NO FEE REQUIRED) FOR THE TRANSITION PERIOD FROM         TO
 
                        COMMISSION FILE NUMBER 333-16011
 
                            ------------------------
 
                             FIRST MARINER BANCORP
                 (Name of small business issuer in its charter)
 
<TABLE>
<S>                                              <C>
                   MARYLAND                                        52-1834860
        (State of other jurisdiction of                         (I.R.S. Employer
        incorporation or organization)                         Identification No.)
 
              BALTIMORE, MARYLAND                                     21224
   (Address of principal executive offices)                        (Zip Code)
</TABLE>
 
                    Issuer's telephone number (410) 342-2600
 
      Securities registered under Section 12(b) of the Exchange Act: NONE
 
         Securities registered under Section 12(g) of the Exchange Act:
 
                     COMMON STOCK, par value $.05 per share
 
                                (Title of Class)
 
                            ------------------------
 
    Check whether the issuer(1) filed all reports required to be filed by
Section 13 or 15(d) of the Securities Exchange Act during the past 12 months (or
for such shorter period that the registrant was required to file such reports,
and (2) has been subject to such filing requirements for the past 90 days. 
Yes /X/ No / /
 
    Check if disclosure of delinquent filers in response to Item 405 of
Regulation S-B is not contained in this form, and no disclosure will be
contained, to the best of registrant's knowledge, in definitive proxy or
information statements incorporated by reference in Part III of this Form 10-KSB
or any amendment to this Form 10-KSB. / /
 
    The issuer's revenues for its most recent year were $16,669,689.
 
    The aggregate market value of the voting stock held by non-affiliates of the
registrant as of March 20, 1998 was $50,208,603.
 
    The number of shares outstanding of the registrant's common stock, as of
March 20, 1998, was 2,869,063 shares.
 
                      DOCUMENTS INCORPORATED BY REFERENCE
 
First Mariner Bancorp's definitive Proxy Statement dated April 10, 1998 for the
1998 annual meeting of shareholders--Part III.
 
           TRANSITIONAL SMALL BUSINESS DISCLOSURE FORMAT: YES / /  NO /X/
 
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


<PAGE>

                             [LETTERHEAD]

The Board of Directors
First Mariner Bancorp:

     We have audited the accompanying consolidated statements of financial 
condition of First Mariner Bancorp and subsidiary (the Company) as of 
December 31, 1997 and 1996 and the related consolidated statements of 
operations, stockholders' equity and cash flows for the years then ended. 
These consolidated financial statements are the responsibility of the 
Company's management. Our responsibility is to express an opinion on these 
consolidated financial statements based on our audits.

     We conducted our audits in accordance with generally accepted auditing 
standards. Those standards require that we plan and perform the audit to 
obtain reasonable assurance about whether the financial statements are free 
of material misstatement. An audit includes examining, on a test basis, 
evidence supporting the amounts and disclosures in the financial statements. 
An audit also includes assessing the accounting principles used and 
significant estimates made by management, as well as evaluating the overall 
financial statement presentation. We believe that our audits provide a 
reasonable basis for our opinion.

     In our opinion, the consolidated financial statements referred to above 
present fairly, in all material respects, the financial position of the 
Company as of December 31, 1997 and 1996, and the results of their operations 
and their cash flows for the years then ended, in conformity with generally 
accepted accounting principles.

KPMG Peat Marwick LLP

Baltimore, MD
February 27, 1998

<PAGE>

SIGNATURES

    Pursuant to the requirements of Section 13 or 15 (d) of the Securities
Exchange Act of 1934, the Registrant has duly caused this report to be signed on
its behalf by the undersigned, thereunto duly authorized.



                                 FIRST MARINER BANCORP



                                 By:
                                    -------------------------------------------
                                                   Edwin F. Hale Sr.
                                          Chairman and Chief Executive Officer


    Pursuant to the requirements of the Securities Exchange Act of 1934, this
report has been signed below by the following persons on behalf of the
Registrant and in the capacities and on the dates indicated.

<TABLE>

<S>                                            <C>                                  <C>   
                                               Chairman and Chief
-------------------------------------------    Executive Officer                    ,1998
         Edwin F. Hale, Sr.                    (Principal Executive Officer)
                                               Director, President and Chief
-------------------------------------------    Operating Officer                    ,1998
         Joseph A. Cicero

-------------------------------------------    Director                             ,1998
         George H. Mantakos

-------------------------------------------    Controller (Principal                ,1998
         Kevin M. Healey                          Financial Officer)

-------------------------------------------
         Barry B. Bondroff                     Director                             ,1998

-------------------------------------------
         Rose M. Cernak                        Director                             ,1998

-------------------------------------------
         Christopher P. D'Anna                 Director                             ,1998

-------------------------------------------
         Bruce H. Hoffman                      Director                             ,1998

-------------------------------------------
         Melvin S. Kabik                       Director                             ,1998

-------------------------------------------
         R. Andrew Larkin                      Director                             ,1998

-------------------------------------------
         Jay J.J. Matriccinai                  Director                             ,1998

-------------------------------------------
         Dennis C. McCoy                       Director                             ,1998

-------------------------------------------
         Walter L. McManus, Jr.                Director                             ,1998

-------------------------------------------
         James P. O'Conor                      Director                             ,1998

-------------------------------------------
         John J. Oliver, Jr.                   Director                             ,1998

-------------------------------------------
         Hanan Y. Sibel                        Director                             ,1998

-------------------------------------------
         Leonard Stoler                        Director                             ,1998

-------------------------------------------
         Governor William Donald Schaefer      Director                             ,1998
</TABLE>