Karl S. Brown, 75, a retired government public information officer, died of cancer Sunday at his home in Washington.

He retired in 1972 from the public affairs staff of the Department of Housing and Urban Development.

Mr. Brown came her in 1952 as a public affairs officer with the State Department. He later was a speech writer for the administrator of Housing and Urban Affairs and director of public affairs for four years for the Urban Renewal Administration.

Born in Allentown, Pa., Mr. Brown graduated from Mercersbury Academy and Yale University.

From 1923 to 1942, he worked in New York for the J. Walter Thompson advertising agency, as a securities analyst for the New York Stock Exchange, as a business-financial writer for Newsweek, Fortune and Today magazines, and as assistant director of market research for the Can Manufacturers Institute.

He served in the Navy during World War II, seeing duty in the European greater, and was discharged with the rank of lieutenant commander.

He then worked as an information officer for the War Assets Administration and as a free-lance writer before coming here.

Mr. Brown was a member of the Army and Navy Club, the Yale clubs of Washington ane New York City, and the Sons of the American revolution.

He is survived by his wife, Mary-Louise Kimmel Brown, of the home, and a stepson, Josiah F. Hill of Lebanon, N.H.

The family suggests that expressions of sympathy may be in the form of contributions to the American Cancer Society.