Professional Standards for Government Attorneys Act of 1999 - Amends the Federal judicial code to provide that, subject to any uniform national rule prescribed by the U.S. Supreme Court, the standards of professional conduct governing a Government attorney shall be: (1) with respect to conduct in connection with a proceeding in or before a court, the standards established by the rules and decisions of that court; (2) with respect to conduct in connection with a pending or contemplated grand jury proceeding, the standards established by the rules and decisions of the court under whose authority the grand jury was impaneled; and (3) with respect to all other conduct, the standards established by the rules and decisions of the State in which the attorney is licensed to practice, with provisions applicable if the attorney is licensed to practice in more than one State.

Requires the Judicial Conference of the United States to submit to the Chief Justice of the United States a report that shall include recommendations with respect to amending the Federal Rules of Civil and Criminal Procedure to provide for such a uniform national rule. Directs the Judicial Conference, in developing recommendations, to consider: (1) the needs and circumstances of multi-forum and multi-jurisdictional litigation; (2) the special needs and interests of the United States in investigating and prosecuting violations of Federal criminal and civil law; and (3) practices that are approved under Federal statutory or case law or that are otherwise consistent with traditional Federal law enforcement techniques.

Specifies that nothing in this Act may be construed to abridge, enlarge, or modify the power of the Supreme Court or of any court established by an Act of Congress to prescribe standards of professional conduct for attorneys practicing in and before the Federal courts, including Government attorneys.