Certification Pursuant to 18 U.S.C. 1350, as adopted pursuant to Section 906 of
the Sarbanes-Oxley Act of 2002.

I, Gifford R. Zimmerman, Chief Administrative Officer of Nuveen Maryland
Dividend Advantage Municipal 3 (the "Fund"), certify that:

     1.   The Form N-CSR of the Fund for the period ended May 31, 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.

A signed original of this written statement required by Section 906, or other
document authenticating, acknowledging, or otherwise adopting the signature that
appears in typed form within the electronic version of this written statement
required by Section 906, has been provided to Nuveen Maryland Dividend Advantage
Municipal 3 and will be retained by Nuveen Maryland Dividend Advantage Municipal
3 and furnished to the Securities and Exchange Commission or its staff upon
request.

Date: August 1, 2003
      -----------------------

                                           /s/ Gifford R. Zimmerman
                                               ---------------------
                                               Chief Administrative Officer
                                               (chief executive officer)



Certification Pursuant to 18 U.S.C. 1350, as adopted pursuant to Section 906 of
the Sarbanes-Oxley Act of 2002.

I, Stephen D. Foy, Vice President and Controller of Nuveen Maryland Dividend
Advantage Municipal 3 (the "Fund), certify that:

     1.   The Form N-CSR of the Fund for the period ended May 31, 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.

A signed original of this written statement required by Section 906, or other
document authenticating, acknowledging, or otherwise adopting the signature that
appears in typed form within the electronic version of this written statement
required by Section 906, has been provided to Nuveen Maryland Dividend Advantage
Municipal 3 and will be retained by Nuveen Maryland Dividend Advantage Municipal
3 and furnished to the Securities and Exchange Commission or its staff upon
request.


Date: August 1, 2003
      -----------------------

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