Certification Pursuant to 18 U.S.C. 1350, as adopted pursuant to Section 906 of
the Sarbanes-Oxley Act of 2002; provided by the Chief Executive Officer and
Chief Financial Officer, based on each such officer's knowledge and belief.

The undersigned officers of Nuveen Maryland Dividend Advantage Municipal Fund 3
(the "Fund"), certify that, to the best of each such officer's knowledge and
belief:

     1.   The Form N-CSR of the Fund for the period ended November 30, 2003
          (the "Report") fully complies with the requirements of Section 13(a)
          or 15(d) of the Securities Exchange Act of 1934; and

     2.   The information contained in the Report fairly presents, in all
          material respects, the financial condition and results of operations
          of the Fund.

Date: February 4, 2004
      -----------------------

                                           /s/ Gifford R. Zimmerman
                                               ---------------------
                                               Chief Administrative Officer
                                               (Chief Executive Officer)

                                           /s/ Stephen D. Foy
                                               ---------------------
                                               Vice President, Controller
                                               (Chief Financial Officer)