Otto John Munz, 73, a patent attorney in the Washington area for many years and the holder of about 15 patents on inventions of his own, died Wednesday at the National Hospital in Arlington following a stroke.

Mr. Munz was born in Horazdovice, Bohemia, Czechoslovakia. He earned a law degree at Charles University in Prague and practiced there from 1931 to 1939. In the latter year, he moved to Toronto, Canada, where he became a patent agent.

In 1946, he settled in Alexandria and worked as a self-employed patent searcher. He also attended George Washington University, where he took a master's degree in comparative law in 1952 and then he was admitted to the bar. m

For the next four years, he was an attorney specializing in patents for the Office of Naval Research. In 1956, he established a private practice in patent law with offices in Crystal City and continued that work until his death.

Mr. Munz lived in Annapolis from 1949 to 1968 and while there was a founder of the Unitarian Church of Anne Arundel County. He had lived in Arlington since then.

He was a member of the D.C., Maryland and American Patent Law Association. He was a member of the bar of the U.S. Supreme Court of Customs and Patent Appeals.

Survivors include his wife, Gerta H., of Arlington; two daughters, Eva M. Asher, of Annopolis, and Jane M. Taliaferro, of Arlington; one sister, Helen Munz, of Toronto, and three grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the American Heart Association.