<PAGE>

                                 United States
                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549
                                   FORM 10-K
(Mark One)

[X]    ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
       EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 1999
                          -----------------
                                      OR
[ ]    TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
       EXCHANGE ACT OF 1934

For the transition period from                         to
                               -----------------------    ----------------------

Commission file number                       0-5127
                       ---------------------------------------------------------

                       Mercantile Bankshares Corporation
                       ---------------------------------
            (Exact name of registrant as specified in its charter)

            Maryland                                       52-0898572
----------------------------------                    -------------------
  State or other jurisdiction of                      (I.R.S. Employer
  incorporation or organization                       Identification No.)

Two Hopkins Plaza, P. O. Box 1477, Baltimore, Maryland           21203
------------------------------------------------------   ---------------------
      (Address of principal executive offices)                 (Zip Code)

Registrant's telephone number, including area code        (410) 237-5900
                                                         ---------------------
Securities registered pursuant to Section 12(b) of the Act:

       Title of each class             Name of each exchange on which registered
             None                                          None
-------------------------------        -----------------------------------------
-------------------------------        -----------------------------------------

          Securities registered pursuant to section 12(g) of the Act:
                          Common Stock ($2 par value)
                    ---------------------------------------
                               (Title of class)
                             Stock Purchase Rights
                 --------------------------------------------
                               (Title of class)

         Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 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
                                                ---           ---

         Indicate by check mark if disclosure of delinquent filers pursuant to
Item 405 of Regulation S-K is not contained herein, and will not 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-K or any
amendment to this Form 10-K.  [X]

         At February 29, 2000, the aggregate market value of shares of Common
Stock held by non-affiliates of Registrant (including fiduciary accounts
administered by affiliates) was $1,665,579,293 based on the last sale price on
the Nasdaq National Market on February 29, 2000.

         As of February 29, 2000, 68,434,209 shares of common stock were
outstanding.

         Documents Incorporated by Reference: Parts I, II and IV - Portions of
         -----------------------------------
Registrant's Annual Report to Stockholders for year ended December 31, 1999, as
indicated, Part III - Definitive Proxy Statement of Registrant filed with the
Securities and Exchange Commission under Regulation 14A.

                                       1
<PAGE>

                                    PART I

ITEM 1.  BUSINESS
-------  --------
                                    General
                                    -------

         Mercantile Bankshares Corporation was incorporated under the laws of
Maryland on May 27, 1969. It is a bank holding company registered under the Bank
Holding Company Act of 1956. Mercantile Bankshares Corporation is referred to in
this report as "Mercshares" or "Registrant."

         Mercshares directly owns all of the outstanding stock of 21 Affiliated
Banks and directly or indirectly owns all of the outstanding stock of certain
other Affiliates. For purposes of segment reporting, two operating components
have been identified. They are (1) the lead bank, Mercantile-Safe Deposit and
Trust Company (including its Banking and Trust Divisions), and (2) twenty
Community Banks. The entities making up each component are identified below,
with headquarters locations.

                           Lead Bank and Affiliates
                           ------------------------

Mercantile-Safe Deposit and Trust Company             Baltimore, Maryland
         Mercantile Mortgage Corporation
         Hopkins Plaza Agency, Inc.
         MBC Leasing Corp.
MBC Agency, Inc.
         Mercantile Life Insurance Company


                                Community Banks
                                ---------------

The Annapolis Banking and Trust Company               Annapolis, Maryland
Bank of Southern Maryland                             LaPlata, Maryland
Calvert Bank and Trust Company                        Prince Frederick, Maryland
The Chestertown Bank of Maryland                      Chestertown, Maryland
The Citizens National Bank                            Laurel, Maryland
County Banking & Trust Company                        Elkton, Maryland
The Fidelity Bank                                     Frostburg, Maryland
The First National Bank of St. Mary's                 Leonardtown, Maryland
The Forest Hill State Bank                            Bel Air, Maryland
Fredericktown Bank & Trust Company                    Frederick, Maryland
Peninsula Bank                                        Princess Anne, Maryland
The Peoples Bank of Maryland                          Denton, Maryland
Potomac Valley Bank                                   Gaithersburg, Maryland
St. Michaels Bank                                     St. Michaels, Maryland
The Sparks State Bank                                 Sparks, Maryland
Westminster Bank and Trust Company
 of Carroll County                                    Westminster, Maryland

                                       2
<PAGE>

Baltimore Trust Company                               Selbyville, Delaware
Farmers & Merchants Bank - Eastern Shore              Onley, Virginia
The National Bank of Fredericksburg                   Fredericksburg, Virginia
Marshall National Bank and Trust Company              Marshall, Virginia

         For certain financial, personnel and office location information
concerning the companies listed above, see pages 53 to 59 of the Registrant's
Annual Report to Stockholders for the year ended December 31, 1999, which
information is incorporated by reference herein.

         Mercshares periodically reviews and considers possible acquisitions of
banks and corporations performing related activities and discusses such possible
acquisitions with managements of the subject companies, and such acquisitions
may be made from time to time. Acquisitions are normally subject to regulatory
approval.

         On January 20, 2000, Mercshares entered into an agreement with Union
National Bancorp, Inc., owner of The Union National Bank of Westminster, for a
merger of Union National Bancorp, Inc. into Mercshares and of The Union National
Bank of Westminster into our affiliate, Westminster Bank and Trust Company of
Carroll County. The Union National Bank of Westminster operates nine banking
offices in Carroll County, Maryland with total assets of approximately $300
million at December 31, 1999. The agreement provides for a tax- free exchange of
1.15 shares of Mercshares common stock for each outstanding share of common
stock of Union National Bancorp, Inc. There are 1,965,349 shares of Union
National Bancorp, Inc. outstanding, plus options for 60,936 shares which may be
exercised before the closing. Completion of the transaction is subject to
regulatory approvals, approval by the stockholders of Union National Bancorp and
other conditions.

                                  Operations
                                  ----------

         Mercantile-Safe Deposit and Trust Company and the Community Banks are
engaged in a general commercial and retail banking business with normal banking
services, including acceptance of demand, savings and time deposits and the

                                       3
<PAGE>

making of various types of loans. Mercantile-Safe Deposit and Trust Company
offers a full range of personal trust services, investment management services
and (for corporate and institutional customers), investment advisory, financial
and pension and profit sharing services. As of December 31, 1999, assets under
the investment supervision of the Trust Division had an estimated value of $13.9
billion, assets held in its personal and corporate custody accounts had an
estimated value of $24.3 billion and assets held in escrow accounts had an
estimated value of $12.6 million.

         Mercantile Mortgage Corporation, through offices in Maryland and
Delaware, arranges for and services various types of mortgage loans as principal
and as agent primarily for non-affiliated institutional investors and also for
the Affiliated Banks.

         Hopkins Plaza Agency, Inc. acts as agent in the sale of fixed rate
annuities, and MBC Leasing Corp. provides tax oriented and finance leases of
equipment.

         MBC Agency, Inc., provides, under group policies, credit life insurance
in connection with extensions of credit by Affiliated Banks. Mercantile Life
Insurance Company reinsures the insurance provided by MBC Agency, Inc.

         MBC Realty, LLC owns and operates various properties used by
Mercantile-Safe Deposit and Trust Company.

         For segment reporting information, see the following portions of the
Registrant's Annual Report to Stockholders for the year ended December 31, 1999,
which information is incorporated by reference herein: Note 15 of Notes to
Financial Statements on pages 43 and 44 of the Annual Report, and information
under the caption "Segment Reporting" on page 12 of the Annual Report.

                            Statistical Information
                            -----------------------

         The statistical information required in this Item 1 is incorporated by
reference to the information appearing in Registrant's Annual Report to
Stockholders for the year ended December 31, 1999, as follows:

                                       4
<PAGE>

<TABLE>
<CAPTION>

Disclosure Required by Guide 3           Reference to 1999 Annual Report
------------------------------           -------------------------------
<S>                                      <C>
(I)        Distribution of Assets,
           Liabilities and Stockholder
           Equity; Interest Rates and
           Interest Differentials           ..................Analysis of Interest Rates and Interest
                                                              Differentials (pages 8-9)
                                            ..................Rate/Volume Analysis (page 10)
                                            ..................Non-performing Assets (pages 17-18)

(II)       Investment Portfolio             ..................Bond Investment Portfolio (page 13)

(III)      Loan Portfolio                   ..................Year-End Loan Data (page 49)
                                            ..................Loan Maturity Schedule (page 19)
                                            ..................Asset/Liability and Liquidity
                                                              Management (pages 21-22)
                                            ..................Non-performing Assets (pages 17-18)
(IV)       Summary of Loan Loss
           Experience                       ..................Allowance for Loan Losses
                                                              (pages 15-17)
                                                              and Credit Risk Analysis (page 16)

                                            ..................Allocation of Allowance for Loan Losses
                                                              (page 15)

(V)        Deposits                         ..................Analysis of Interest Rates and Interest
                                                              Differentials (pages 8-9)
                                            ..................Notes to Financial Statements,
                                                              Note 5 - Deposits (page 35)
(VI)       Return on Equity
           and Assets                       ..................Return on Equity and Assets (page 51)


(VII)      Short-Term Borrowings            ..................Notes to Financial Statements,
                                                              Note 6 (page36)
</TABLE>

                                       5
<PAGE>

                                   Employees
                                   ---------

         At December 31, 1999, Mercshares and its Affiliates had approximately
921 officers and 1,875 other employees. Of these, Mercantile-Safe Deposit and
Trust Company employed 414 officers and 636 other employees and the Community
Banks had 505 officers and 1,219 other employees.

                                  Competition
                                  -----------

         The banking business, in all of its phases, is highly competitive.
Within their service areas, Mercantile-Safe Deposit and Trust Company and the
Community Banks compete with commercial banks (including local banks and
branches or affiliates of other larger banks), savings and loan associations and
credit unions for loans and deposits, and with insurance companies and other
financial institutions for various types of loans. There is also competition for
commercial and retail banking business from banks and financial institutions
located outside our service areas. Interstate banking is now an established part
of the competitive environment.

         While Mercshares is the second largest bank holding company
headquartered in Maryland, it is the largest independent bank holding company in
the state. Mercantile-Safe Deposit and Trust Company is the fourth largest
commercial bank in Maryland. During 1999, Mercshares also competed with
Maryland-based bank subsidiaries of the first, second, sixth and ninth largest
bank holding companies in the United States as well as banking subsidiaries of
other non-Maryland bank holding companies. Measured in terms of assets under
investment supervision, Mercantile-Safe Deposit and Trust Company believes it is
one of the largest trust institutions in the southeastern United States.
Mercantile-Safe Deposit and Trust Company competes for various classes of
fiduciary and investment advisory business with other banks and trust companies,
insurance companies, investment counseling firms, mutual funds and others.

                                       6
<PAGE>

         Mercantile Mortgage Corporation is one of many competitors in its area
of activity. MBC Agency, Inc. is limited to providing credit life, health and
accident insurance in connection with credit extended by the Affiliated Banks.
Hopkins Plaza Agency, Inc. and MBC Leasing Corp. commenced business in 1996 and
are small competitors in their areas of activity.

         The 20 Community Banks ranged in asset size from $43 million to $617
million, at December 31, 1999. They face competition in their own local service
areas as well as from the larger competitors mentioned above.

         The enactment of recent federal legislation governing the financial
services industry, discussed below, may have the effect of increasing
competition among banks and other financial institutions.

                          Supervision and Regulation
                          --------------------------
Mercshares
----------

         Mercshares, as a registered bank holding company, is subject to
regulation and examination by the Board of Governors of the Federal Reserve
System under the Bank Holding Company Act of 1956 (the "Act") and is required to
file with the Board of Governors quarterly and annual reports and such
additional information as the Board of Governors may require pursuant to the
Act. With various exceptions, Mercshares is prohibited from acquiring direct or
indirect ownership or control of more than 5% of any class of the voting shares
of any company which is not a bank or bank holding company and from engaging in
any business other than that of banking or of managing or controlling banks or
of furnishing services to, or performing services for, its Affiliated Banks. The
Act and Regulations promulgated under the Act require prior approval of the
Board of Governors of the Federal Reserve System of the acquisition by
Mercshares of more than 5% of any class of the voting shares of any additional
bank.

                                       7
<PAGE>

         Further, under Section 106 of the 1970 Amendments to the Act and the
Board's Regulations, bank subsidiaries of bank holding companies are limited in
engaging in certain tie-in arrangements with bank holding companies and their
non-bank subsidiaries in connection with any extension of credit or provision of
any property or services, subject to various exceptions.

         The Act, generally, has restricted activities of bank holding companies
and their subsidiaries to banking, and the business of managing and controlling
banks, and to other activities which have been determined by the Board of
Governors of the Federal Reserve System to be so closely related to banking or
managing or controlling banks as to be a proper incident thereto. Mercshares has
also been subject to certain restrictions with respect to engaging in the
securities business.

         It is Federal Reserve Policy that a bank holding company should serve
as a source of financial and managerial strength for and commit resources to
support each of its subsidiary banks even in circumstances in which it might not
do so (or may not legally be required or financially able to do so) absent such
a policy.

         Changes in control of Mercshares and its Affiliated Banks are regulated
under the Bank Holding Company Act of 1956, the Change in Bank Control Act of
1978 and various state laws.

New Federal Legislation
-----------------------

         The enactment in November, 1999 of the Graham-Leach-Bliley Act (the
"New Act"), parts of which have become effective, represents the culmination of
years of effort to repeal the provisions in the Banking Act of 1933 (generally
known as "Glass Steagall") and restrictions in the Bank Holding Company Act of
1956 that, respectively, limited affiliations among, and overlapping business
activities in, the banking, securities and insurance industries. Broadly
speaking, through the establishment of a regulatory structure that permits a
bank

                                       8
<PAGE>

holding company to elect "financial holding company" status, the New Act will
permit, within a holding company system, a full range of banking, securities and
insurance activities, including securities and insurance underwriting, as well
as, with certain restrictions, merchant banking activities. The election is only
available to bank holding companies whose bank and thrift subsidiaries are well
capitalized, well managed, and have satisfactory Community Reinvestment Act
ratings. With exceptions for insurance underwriting and merchant banking, the
New Act would also permit comparable expansion of national bank activities by
banks meeting similar criteria, together with certain additional firewall and
other requirements, through "financial subsidiaries" of national banks.
Similarly, as a matter of Federal law, but still subject to State law, the New
Act greatly expands the potential financial activities of subsidiaries of State
banks.

         If Mercshares were to elect financial holding company status under the
New Act, it would be permitted to engage in the full range of securities and
insurance activities authorized by the New Act, including securities and
insurance underwriting, as well as certain permitted merchant banking
activities. However, Mercshares does not need to elect financial holding company
status in order to engage in the businesses in which it is currently engaged.

         The New Act is also intended to ensure that banking activities are
regulated by bank regulators, securities activities are regulated by securities
law regulators, and insurance activities are regulated by insurance regulators.
In other words, it is intended to incorporate a system of functional regulation,
although it retains the role of the Federal Reserve Board as the umbrella
supervisor for holding companies. Consequently, effective May 12, 2001, various
securities activities of banks may become subject to regulation by the
Securities and Exchange Commission.

         With respect to the functional regulation goal of the New Act, various


                                       9
<PAGE>

provisions are expected to have the effect of banks "pushing out' those
securities activities that have now become subject to Securities and Exchange
Commission regulation into separate brokerage subsidiaries or affiliates.
However, defined traditional banking activities, which include most of
Mercantile-Safe Deposit and Trust Company's current Trust Division activities
should not trigger Securities and Exchange Commission regulation or the so-
called "push-out" process.

         Many of the provisions of the New Act require and anticipate extensive
new regulations, some of which have already been promulgated or proposed.

         While it is now difficult to predict the impact of the New Act with
precision, it does not appear that Mercshares and its affiliates will be
precluded from engaging in their existing activities. It is possible, however,
that some activities will need to be conducted in one or more separate
subsidiaries subject to Securities and Exchange Commission regulation.

Affiliated Banks
----------------

         All Affiliated Banks, with the exception of The Citizens National Bank,
Baltimore Trust Company, Farmers & Merchants Bank - Eastern Shore, The First
National Bank of St. Mary's, The National Bank of Fredericksburg and Marshall
National Bank and Trust Company are Maryland banks, subject to the banking laws
of Maryland and to regulation by the Commissioner of Financial Regulation of
Maryland, who is required by statute to make at least one examination in each
calendar year (or at 18-month intervals if the Commissioner determines that an
examination is unnecessary in a particular calendar year). Their deposits are
insured by, and they are subject to certain provisions of Federal law and
regulations and examination by, the Federal Deposit Insurance Corporation.

         In addition, The Annapolis Banking and Trust Company, The Forest Hill
State Bank and St. Michaels Bank are members of the Federal Reserve System, and
are

                                       10
<PAGE>

thereby subject to regulation by the Board of Governors of that System.

         The Citizens National Bank, The First National Bank of St. Mary's, The
National Bank of Fredericksburg and Marshall National Bank and Trust Company are
national banks subject to regulation and regular examination by the Comptroller
of the Currency in addition to regulation and examination by the Board of
Governors of the Federal Reserve System and the Federal Deposit Insurance
Corporation, which insures their deposits.

         Farmers & Merchants Bank - Eastern Shore is a Virginia bank, subject to
the banking laws of Virginia and to regulation by its State Corporation
Commission, which is required by statute to make at least one examination in
every three year period. Its deposits are insured by, and it is subject to
certain provisions of Federal law and regulation and examination by, the Federal
Deposit Insurance Corporation.

         Baltimore Trust Company is a Delaware bank, subject to the banking laws
of Delaware and to regulation by the Delaware State Bank Commissioner, who is
required by statute to make periodic examinations. Its deposits are insured by,
and it is subject to certain provisions of Federal law and regulation and
examination by the Federal Deposit Insurance Corporation.

         Mercshares and its Affiliates are subject to the provisions of Section
23A of the Federal Reserve Act which limit the amount of loans or extensions of
credit to, and investments in, Mercshares and its nonbanking Affiliates by the
Affiliated Banks, and Section 23B of the Federal Reserve Act which requires that
transactions between the Affiliated Banks and Mercshares and its nonbanking
Affiliates be on terms and under circumstances that are substantially the same
as with non-affiliates. Under the Financial Institutions Reform, Recovery, and
Enforcement Act of 1989, there are circumstances under which Affiliated Banks
could be responsible to the Federal Deposit Insurance Corporation for losses
incurred by it with respect to other Affiliated Banks.

                                       11
<PAGE>

Other Affiliates
----------------

         As affiliates of Mercshares, the nonbanking Affiliates are subject to
examination by the Board of Governors of the Federal Reserve System and, as
affiliates of the Affiliated Banks, they are subject to examination by the
Federal Deposit Insurance Corporation and the Commissioner of Financial
Regulation of Maryland. In addition, MBC Agency, Inc., Mercantile Life Insurance
Company and Hopkins Plaza Agency, Inc. are subject to licensing and regulation
by state insurance authorities.

                          Effects of Monetary Policy
                          --------------------------

         All commercial banking operations are affected by the Federal Reserve
System's conduct of monetary policy and its policies change from time to time
based on changing circumstances. A function of the Federal Reserve System is to
regulate the national supply of bank credit in order to achieve economic results
deemed appropriate by its Board of Governors, including efforts to combat
unemployment, recession or inflationary pressures. Among the instruments of
monetary policy used to implement these objectives are open market operations in
the purchase and sale of U.S. Government securities, changes in the discount
rate charged on bank borrowings and changes in reserve requirements against bank
deposits. These means are used in varying combinations to influence the general
level of interest rates and the general availability of credit. More
specifically, actions by the Board of Governors of the Federal Reserve influence
the levels of interest rates paid on deposits and other bank funding sources and
charged on bank loans as well as the level of availability of bank funds with
which loans and investments can be made.

                             Cautionary Statement
                             --------------------

         This Annual Report on Form 10-K contains forward-looking statements
within

                                       12
<PAGE>

the meaning of and pursuant to the safe harbor provisions of the Private
Securities Litigation Reform Act of 1995. A forward-looking statement
encompasses any estimate, prediction, opinion or statement of belief contained
in this report, and the underlying management assumptions. Examples are
statements concerning completion of pending acquisitions, competitive
conditions, effects of monetary policy, and the potential impact of legislation.
A similar cautionary statement, concerning the content of the Registrant's
Annual Report to Stockholders for the year ended December 31, 1999, is contained
in that Report.

         With respect to effects of monetary policy, the monetary policies of
bank regulatory and other authorities have affected the operating results of
commercial banks in the past and are expected to continue to do so in the
future. In view of changing conditions in the national economy, in the money
markets, and in the relationships of international currencies, as well as the
effect of legislation and of actions by monetary and fiscal authorities, no
prediction can be made as to possible future changes in interest rates, deposit
levels, loan demand, or the business and earnings of the Affiliated Banks.

ITEM 2.  PROPERTIES
-------  ----------

         The main offices of Mercshares and Mercantile-Safe Deposit and Trust
Company are located in a 21-story building at Hopkins Plaza in Baltimore owned
by MBC Realty, LLC, a wholly owned subsidiary of Mercshares. At December 31,
1999, these offices occupied approximately 145,000 square feet (together with
about 23,000 square feet leased in a nearby building). At December 31, 1999,
Mercantile-Safe Deposit and Trust Company also occupied approximately 132,000
square feet of leased space in a building located in Linthicum, Maryland, in
which its operations and certain other departments are located, and a 7,000
square foot call center facility in Federalsburg, Maryland. The Linthicum and
Federalsburg properties are owned by MBC Realty, LLC. Of the 18 banking and
bank-related offices occupied by Mercantile-Safe Deposit and Trust Company, four
are owned in fee, five are owned subject to ground leases and nine are leased

                                       13
<PAGE>

with aggregate annual rentals of approximately $1,364,000, not including rentals
for the main office and adjacent premises owned by MBC Realty, LLC.

         Of the 165 banking offices of the Community Banks, 95 are owned in fee,
16 are owned subject to ground leases and 54 are leased, with aggregate annual
rentals of approximately $3,591,000 as of December 31, 1999.

ITEM 3.  LEGAL PROCEEDINGS
-------  -----------------

         There was no matter which is required to be disclosed in this Item 3
pursuant to the instructions contained in the form for this Report.

ITEM 4.  SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS
-------  ---------------------------------------------------

         No matter was submitted during the fourth quarter of the fiscal year
covered by this Report to a vote of security holders which is required to be
disclosed pursuant to the instructions contained in the form for this Report.

SPECIAL ITEM:  EXECUTIVE OFFICERS OF THE REGISTRANT
-------------  ------------------------------------

         The Executive Officers of Registrant are:

<TABLE>
<CAPTION>

Name                                        Position                                          Age
----                                        --------                                          ---
<S>                                         <C>                                               <C>
H. Furlong Baldwin                          Chairman of the Board, President                   68
                                             and Chief Executive Officer
J. Marshall Reid/(1)/                       President and Chief                                54
                                             Operating Officer (Mercantile-
                                             Safe Deposit and Trust Company)
Jack E. Steil                               Executive Vice President.                          53
                                            Chairman - Credit Policy
                                             (Mercantile-Safe Deposit
                                             and Trust Company)
Alan D. Yarbro                              General Counsel and Secretary                      58
Terry L. Troupe                             Chief Financial Officer and
                                             Treasurer                                         52
Robert W. Johnson                           Senior Vice President                              57
O. James Talbott, II                        Senior Vice President                              56
</TABLE>

---------------------------

/(1)/Mr. Reid is an officer of Mercantile-Safe Deposit and Trust Company. He is
included above as an executive officer because he participates in policy-making
functions concerning Mercshares.

         No family relationships, as defined by the Rules and Regulations of the
Securities and Exchange Commission, exist among any of the Executive Officers.

         All officers are elected annually by the Board of Directors and hold
office at the pleasure of the Board.

         Mr. Baldwin has been Chairman of the Board of Mercshares since 1984,
and

                                       14
<PAGE>

has been its Chief Executive Officer since 1976. He assumed the presidency
of Mercshares in 1997. He has been Chairman of the Board and Chief Executive
Officer of Mercantile-Safe Deposit and Trust Company since 1976.

         Mr. Reid was elected President and Chief Operating Officer of
Mercantile-Safe Deposit and Trust Company in September, 1997. He joined
Mercantile-Safe Deposit and Trust Company as a Senior Vice President in 1993 and
served as an Executive Vice President from 1994 until September, 1997.

         Mr. Steil was elected Chairman - Credit Policy of Mercantile-Safe
Deposit and Trust Company in September, 1997. He had previously served
Mercantile-Safe Deposit and Trust Company as an Executive Vice President since
1994, and as Senior Vice President from 1988 to 1994. In March, 1999, Mr. Steil
was elected an Executive Vice President of Mercshares.

         Mr. Yarbro has been General Counsel of Mercshares and Mercantile-Safe
Deposit and Trust Company since April, 1996 and was elected Secretary of both
companies in June, 1996. His prior employment was as a partner of Venable,
Baetjer and Howard, LLP, where he practiced law for 29 years.

         Mr. Troupe has been Chief Financial Officer of Mercshares and
Mercantile-Safe Deposit and Trust Company, and Treasurer of Mercshares, since
September, 1996. He was Vice President and Chief Financial Officer of IREX
Corporation, a specialty mechanical insulation contractor and distributor, from
May, 1993 to May, 1996. Prior thereto, Mr. Troupe was Vice Chairman of Meridian
Bancorp, Inc.

         Mr. Johnson has been Senior Vice President of Mercshares since 1989. He
has been a Vice President of Mercantile-Safe Deposit and Trust Company since
1982.

         Mr. Talbott has been a Senior Vice President of Mercshares since 1989.
He has been a Vice President of Mercantile-Safe Deposit and Trust Company since
1977.

                                    PART II
                                    -------

ITEM 5.  MARKET FOR REGISTRANT'S COMMON EQUITY AND RELATED STOCKHOLDER MATTERS
-------  ---------------------------------------------------------------------

         Information required by this Item 5 is incorporated by reference to the
information appearing under the captions "Dividends" and "Recent Common Stock

                                       15
<PAGE>

Prices" on page 23 of the Registrant's Annual Report to Stockholders for the
year ended December 31, 1999.

         The following information is given in response to Item 701 of
Regulation S-K. In December, 1999, two directors of Mercshares received an
aggregate of 1,004 shares of Mercshares common stock, at fair market value, in
lieu of a cash retainer fee, under the Mercshares Retainer Stock Plan for Non
Employee Directors. The shares issuable under the Plan have not been registered
under the Securities Act of 1933 in reliance on Release 33-6188 (1980) and
Release 33-6281 (1981). The only potential Plan participants are outside
directors, currently 13 in number. Mercshares common stock is actively traded on
the Nasdaq National Market. The maximum number of shares (450,000) issuable over
ten years under the Plan is less than 1% of the total shares outstanding.

ITEM 6.  SELECTED FINANCIAL DATA
-------  -----------------------

         The information required by this Item 6 is incorporated by reference to
the information appearing under the caption "Five Year Selected Financial Data"
on page 49 of the Registrant's Annual Report to Stockholders for the year ended
December 31, 1999.

ITEM 7.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
-------  -----------------------------------------------------------------------
         OF OPERATION
         ------------

         The information required by this Item 7 is incorporated by reference to
the information appearing under the caption "Management's Discussion and
Analysis of Financial Condition and Results of Operations" on pages 6 to 24 of
the Registrant's Annual Report to Stockholders for the year ended December 31,
1999.

ITEM 7A. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK.
-------- ----------------------------------------------------------

         The information required by this Item 7A is incorporated by reference
to the information appearing under the captions "Earnings Simulation Model
Projections" and "Asset/Liability and Liquidity Management" on pages 20 and 21-
22 of the Registrant's Annual Report to Stockholders for the year ended December
31, 1999.

ITEM 8.  FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA
-------  -------------------------------------------

         The information required by this Item 8 and the auditors' report
thereon

                                       16
<PAGE>

are incorporated by reference to pages 25 to 48 of the Registrant's
Annual Report to Stockholders for the year ended December 31, 1999.

ITEM 9.  CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND
-------  ---------------------------------------------------------------
         FINANCIAL DISCLOSURE
         --------------------

         There was no matter which is required to be disclosed in this Item 9
pursuant to the instructions contained in the form for this Report.

                                   PART III
                                   --------

ITEM 10. DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT
-------- --------------------------------------------------

         The information required by this Item 10 with respect to the Executive
Officers of Registrant appears in Part I of this Report.

         The remaining information required by this Item 10 is incorporated by
reference to the definitive proxy statement of Registrant filed with the
Securities and Exchange Commission under Regulation 14A.

ITEM 11. EXECUTIVE COMPENSATION
-------- ----------------------

         The information required by this Item 11 is incorporated by reference
to the definitive proxy statement of Registrant filed with the Securities and
Exchange Commission under Regulation 14A.

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT
-------- --------------------------------------------------------------

         The information required by this Item 12 is incorporated by reference
to the definitive proxy statement of Registrant filed with the Securities and
Exchange Commission under Regulation 14A.

ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS
-------- ----------------------------------------------

         The information required by this Item 13 is incorporated by reference
to the definitive proxy statement of Registrant filed with the Securities and
Exchange Commission under Regulation 14A.


                                    PART IV
                                    -------

ITEM 14. EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM 8-K
-------------------------------------------------------------------------

(a)      The following documents are filed as part of this report, except as
         indicated.

         (1) (2) The financial statements and schedules filed herewith or
         incorporated by reference are listed in the accompanying Index to
         Financial Statements.

         (3) Exhibits filed herewith or incorporated by reference herein are set
         forth in the following table prepared in accordance with Item 601 of
         Regulation S-K.

                                       17
<PAGE>

                                 Exhibit Table
                                 -------------


         (3)  Charter and by-laws
              A.  (1)  Articles of Incorporation effective May 27, 1969
                       (Incorporated by reference to Registrant's Registration
                       Statement on Form S-1, No. 2-39545, Exhibit 3-A(1)).

                  (2)  Articles of Amendment effective June 6, 1969
                       (Incorporated by reference to Registrant's Registration
                       Statement on Form S-1, No. 2-39545, Exhibit 3-A)(2)).

                  (3)  Articles Supplementary effective August 28, 1970
                       (Incorporated by reference to Registrant's Registration
                       Statement on Form S-1, No. 2-39545, Exhibit 3-A)(3)).

                  (4)  Articles of Amendment effective December 14, 1970
                       (Incorporated by reference to Registrant's Registration
                       Statement on Form S-1, No. 2-39545, Exhibit 3-A(4)).

                  (5)  Articles Supplementary effective May 10, 1971
                       (Incorporated by reference to Registrant's Registration
                       Statement on Form S-1, No. 2-39545, Exhibit 3-A(5)).

                  (6)  Articles Supplementary effective July 30, 1971
                       (Incorporated by reference to Registrant's Registration
                       Statement on Form S-1, No. 2-41379, Exhibit 3-A(6)).

                  (7)  Articles of Amendment effective May 8, 1986 (Incorporated
                       by reference to Registrant's Annual Report on Form 10-K
                       for the year ended December 31, 1993, Exhibit 3-A(7),
                       Commission File No. 0-5127).

                  (8)  Articles of Amendment effective April 27, 1988
                       (Incorporated by reference to Registrant's Annual Report
                       on Form 10-K for the year ended December 31, 1993,
                       Exhibit 3-A(8), Commission File No. 0-5127).

                  (9)  Articles Supplementary effective September 13, 1989
                       (Incorporated by reference to Registrant's Form 8-K filed
                       September 27, 1989, Exhibit B attached to Exhibit 4-A,
                       Commission File No. 0-5127).

                  (10) Articles Supplementary effective January 3, 1990
                       (Incorporated by reference to Registrant's Form 8-K filed
                       January 9, 1990, Exhibit B attached to Exhibit 4-A,
                       Commission File No. 0-5127).

                  (11) Articles of Amendment effective April 26, 1990
                       (Incorporated by reference to Registrant's Annual Report
                       on Form 10-K for the year ended December 31, 1990,
                       Exhibit 3-A(11), Commission File No. 0-5127).

                  (12) Articles of Amendment effective April 30, 1997
                       (Incorporated by reference to Registrant's Registration
                       Statement on Form S-4, No. 333-43651, Exhibit 3(i)(L)).

                  (13) Articles Supplementary effective June 9, 1999
                       (Incorporated by reference to Registrant's Registration
                       Statement on Form S-8, No. 333-90307, Exhibit 4.1.M).

                                       18
<PAGE>

                  (14) Articles Supplementary effective September 30, 1999
                       (Incorporated by reference to Registrant's Registration
                       Statement on Form S-8, No. 333-90307, Exhibit 4.1.N).

              B.  By-Laws of the Registrant, as amended to date (Incorporated by
                  reference to Registrant's Registration Statement on Form S-8,
                  No. 333-90307, Exhibit 4.2).

         (4)  Instruments defining the rights of security holders, including
              indentures, Charter and by-laws: See Item 14(a)(3) above.

              A.  Rights Agreement dated as of June 8, 1999 between Registrant
                  and the Rights Agent, including Form of Rights Certificate and
                  Articles Supplementary (Incorporated by reference to Form 8-K
                  of Registrant filed June 10, 1999, Exhibit 4-A, Commission
                  File No. 0-5127).

              B.  Amendment No. 1 to Registrant's Registration Statement on Form
                  8-B, amending description of securities previously filed
                  (Incorporated by reference to Form 8 of Registrant filed
                  December 20, 1991, Commission File No. 0-5127).

         (10) Material contracts

              A.  Mercantile Bankshares Corporation and Affiliates Annual
                  Incentive Compensation Plan, as amended through March 10, 1998
                  (Incorporated by reference to Registrant's Annual Report on
                  From 10-K for the year ended December 31, 1997, Exhibit 10 A,
                  Commission File No. 0-5127).

              B.  Dividend Reinvestment and Stock Purchase Plan of Mercantile
                  Bankshares Corporation (Incorporated by reference to the Plan
                  text included in Registrant's Registration Statement on Form
                  S-3, No. 33-44376.)

              C.  Executive Employment Agreement dated March 24, 1982, between
                  Mercantile Bankshares Corporation, Mercantile-Safe Deposit and
                  Trust Company and H. Furlong Baldwin, as amended by Agreements
                  dated March 13, 1984 and December 13, 1988 (Incorporated by
                  reference to Registrant's Annual Report on Form 10-K for the

                                       19
<PAGE>

                  year ended December 31, 1989, Exhibit 10 D, Commission File
                  No. 0-5127), as amended by Agreement dated January 29, 1997
                  (Incorporated by reference to Registrant's Annual Report on
                  Form 10-K for the year ended December 31, 1996, Exhibit 10 C,
                  Commission file No. 0-5127), as amended by Agreement dated
                  January 28, 1999 (Incorporated by reference to Registrant's
                  Annual Report on Form 10-K for the year ended December 31,
                  1998, Exhibit 10C, Commission File No. 0-5127), as amended by
                  Agreement dated January 18, 2000 (filed herewith).

              D.  Deferred Compensation Agreement, including supplemental
                  pension and thrift plan arrangements, dated September 30,
                  1982, between Mercantile-Safe Deposit and Trust Company and H.
                  Furlong Baldwin, as amended by Agreements dated as of October
                  24, 1983, March 13, 1984, January 1, 1987, December 8, 1987
                  and January 1, 1989 (Incorporated by reference to Registrant's
                  Annual Report on Form 10-K for the year ended December 31,
                  1989, Exhibit 10 E, Commission File No. 0-5127), as amended by
                  Agreement dated February 1, 1997 (Incorporated by reference to
                  Registrant's Annual Report on Form 10-K for the year ended
                  December 31, 1996, Exhibit 10 D, Commission File No. 0-5127).

              E.  Mercantile Bankshares Corporation and Participating Affiliates
                  Unfunded Deferred Compensation Plan for Directors, as amended
                  through January 1, 1984 (Incorporated by reference to
                  Registrant's Annual Report on Form 10-K for the year ended
                  December 31, 1989, Exhibit 10 G, Commission File No. 0-5127),
                  as amended and restated by amendment effective December 31,
                  1995 (Incorporated by reference to Registrant's Annual Report
                  on Form 10-K for the year ended December 31, 1995, Exhibit 10
                  F, Commission File No. 0-5127).

              F.  Mercantile Bankshares Corporation Employee Stock Purchase
                  Dividend Reinvestment Plan dated February 13, 1995

                                       20
<PAGE>

                  (Incorporated by reference to Registrant's Annual Report on
                  Form 10-K for the year ended December 31, 1994, Exhibit 10 I,
                  Commission File No. 0-5127).

              G.  Executive Severance Agreement dated as of December 31, 1989
                  between Mercantile Bankshares Corporation and Mercantile-Safe
                  Deposit and Trust Company, and H. Furlong Baldwin
                  (Incorporated by reference to Registrant's Annual Report on
                  Form 10-K for the year ended December 31, 1989, Exhibit 10 Q,
                  Commission File No. 0-5127), as amended by Agreement dated
                  January 29, 1997 (Incorporated by reference to Registrant's
                  Annual Report on Form 10-K for the year ended December 31,
                  1996, Exhibit 10 J, Commission File No. 0-5127), as amended by
                  Agreement dated January 18, 2000 (filed herewith).

              H.  Mercantile Bankshares Corporation (1989) Omnibus Stock Plan
                  (Incorporated by reference to Registrant's Quarterly Report on
                  Form 10-Q for the period ended September 30, 1997, Exhibit 10
                  K, Commission File No. 0-5127).

              I.  Mercantile Bankshares Corporation 1999 Omnibus Stock Plan
                  (Incorporated by reference to Registrant's Registration
                  Statement on Form S-8, No. 333-90307, Exhibit 4.4).

              J.  Mercantile Bankshares Corporation and Participating Affiliates
                  Supplemental Cash Balance Executive Retirement Plan, dated
                  April 27, 1994, effective January 1, 1994 (Incorporated by
                  reference to Registrant's Annual Report on Form 10-K for year
                  ended December 31, 1994, Exhibit 10 R, Commission File No.
                  0-5127).

              K.  Mercantile Bankshares Corporation and Participating Affiliates
                  Supplemental 401(k) Executive Retirement Plan, dated December
                  13, 1994, effective January 1, 1995 (Incorporated by reference
                  to Registrant's Annual Report on Form 10-K for the year ended
                  December 31, 1994, Exhibit 10 S, Commission File No. 0-5127).

                                       21
<PAGE>

              L.  Mercantile Bankshares Corporation Option Agreement with H.
                  Furlong Baldwin (dated August 22, 1995), with respect to
                  120,000 shares after a stock dividend paid in 1997, and as to
                  which the Net Operating Income is that of Mercantile-Safe
                  Deposit and Trust Company (Incorporated by reference to
                  Registrant's Annual Report on Form 10-K for the year ended
                  December 31, 1995, Exhibit 10 Q, Commission File No. 0-5127).

              M.  Mercantile Bankshares Corporation Retainer Stock Plan For Non-
                  Employee Directors dated March 12, 1996 (Incorporated by
                  reference to Registrant's Annual Report on Form 10-K for the
                  year ended December 31, 1995, Exhibit 10 R, Commission File
                  No. 0-5127).

              N.  Supplemental Cash Balance Plan and Thrift Agreement, dated
                  April 12, 1996, between Mercantile Bankshares Corporation and
                  Alan D. Yarbro (Incorporated by reference to Registrant's
                  Quarterly Report on Form 10-Q for the period ended June 30,
                  1996, Exhibit 10 S, Commission File No. 0-5127).

              O.  Executive Severance Agreement, dated as of April 24, 1996,
                  between Mercantile Bankshares Corporation and Alan D. Yarbro
                  (Incorporated by reference to Registrant's Quarterly Report on
                  Form 10-Q for the period ended June 30, 1996, Exhibit 10 T,
                  Commission File No. 0-5127).

              P.  Mercantile Bankshares Corporation Option Agreement with Alan
                  D. Yarbro, dated April 26, 1996 (Incorporated by reference to
                  Registrant's Quarterly Report for the period ended June 30,
                  1996, Exhibit 10 U, Commission File No. 0-5127).

              Q.  Mercantile Bankshares Corporation Option Agreement with J.
                  Marshall Reid, dated August 21, 1995 (Incorporated by
                  reference to Registrant's Annual Report of Form 10-K for the
                  year ended December 31, 1998, Exhibit 10R, Commission File No.
                  0-5127).

                                       22
<PAGE>

              R.  Mercantile Bankshares Corporation Option Agreement with Jack
                  E. Steil, dated August 21, 1995 (Incorporated by reference to
                  Registrant's Annual Report on Form 10-K for the year ended
                  December 31, 1998, Exhibit 10S, Commission File No. 0-5127).

              S.  Mercantile Bankshares Corporation Option Agreement with Terry
                  L. Troupe, dated September 10, 1996 (filed herewith).

         (13) Annual Report to security holders for the year ended December 31,
              1999 (filed herewith).

         (21) Subsidiaries of the Registrant

              Information as to subsidiaries of the Registrant (filed herewith).

         (23) Consent

              Consent of Certified Public Accountants (filed herewith)

         (24) Power of Attorney

              Power of Attorney dated March 14, 2000 (filed herewith)

         (27) Financial Data Schedule (filed herewith)

(b)      No reports on Form 8-K were filed during the last quarter of the period
         covered by this Report.

                                       23
<PAGE>

                         INDEX TO FINANCIAL STATEMENTS

The Report of Independent Certified Public Accountants as pertaining to the
    Consolidated Financial Statements of Mercantile Bankshares Corporation and
    Affiliates and related notes is incorporated by reference to page 25 of the
    Registrant's Annual Report to Stockholders for the year ended December 31,
    1999.

Consolidated Financial Statements and related notes are incorporated by
    reference to the Registrant's Annual Report to Stockholders for the year
    ended December 31, 1999, and may be found on the pages of said Report as
    indicated in parentheses:

         Consolidated Balance Sheets, December 31, 1999 and 1998 (page 26)
         Statement of Consolidated Income for the years ended December 31, 1999,
           1998 and 1997 (page 27)
         Statement of Consolidated Cash Flows for the years ended December 31,
           1999, 1998 and 1997 (pages 28 and 29)
         Statement of Changes in Consolidated Stockholders' Equity for the years
           ended December 31, 1999, 1998 and 1997 (page 30)
         Notes to Consolidated Financial Statements (pages 31 to 48)

Supplementary Data:

    Quarterly Results of Operations are incorporated by reference to the
         information appearing under the caption "Quarterly Results of
         Operations" on page 45 of the Registrant's Annual Report to
         Stockholders for the fiscal year ended December 31, 1999.

    Financial Statement Schedules are omitted because of the absence of the
         conditions under which they are required or because the information
         called for is included in the Consolidated Financial Statements or
         notes thereto.

                                       24
<PAGE>

                                  Signatures
                                  ----------

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

MERCANTILE BANKSHARES CORPORATION

By:      /S/ H. Furlong Baldwin                            March 27, 2000
         ---------------------------------------
         H. Furlong Baldwin, Chairman of the
         Board, President and Chief Executive Officer

         Pursuant to the requirements of the Securities 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:

Principal Executive Officer

/S/ H. Furlong Baldwin                                     March 27, 2000
------------------------------------
H. Furlong Baldwin, Chairman of the
Board, President and Chief Executive Officer

Principal Financial Officer

/S/ Terry L. Troupe                                        March 27, 2000
------------------------------------
Terry L. Troupe
Chief Financial Officer

Principal Accounting Officer

/S/ Diana Nelson                                           March 27, 2000
------------------------------------
Diana Nelson
Controller



A majority of the Board of Directors:

George L. Bunting, Jr., Christian H. Poindexter, Freeman A. Hrabowski, III,
Darrell D. Friedman, Morton B. Plant, William R. Brody, Donald J. Shepard, Mary
Junck, Robert A. Kinsley, Thomas M. Bancroft, Jr., William J. McCarthy.

By:      /S/ H. Furlong Baldwin                            March 27, 2000
         --------------------------------
         H. Furlong Baldwin
         For Himself and as Attorney-in-Fact

                                       25