Reginald Zalles, 69, a former national director of Americans for Democratic Action, died Friday at Suburban Hospital in Bethesda.

Mr. Zalles was national director of the ADA from 1951 to 1954. He then served until 1968 as the organization's membership secretary and treasurer. He also was chairman of the Montgomery County Chapter of the ADA in 1955 and of the D.C. Chapter in 1959.

He was active in Democratic Party affairs and was a treasurer of the Montgomery County Democratic Central Committee. He also was a trustee of the Montgomery County Art Center.

Mr. Zalles was born in Washington. He grew up here and in La Paz, Bolivia. In 1932, he graduated from Williams College. From 1935 to 1940, he was on the faculty of the Henry George School of Social Science and taught in Boston and New York.

During World War II, he was an infantry officer in the Army and served in Italy and France. He won the Bronze Star and the Purple Heart and was discharged with the rank of captain.

He earned a master's degree at Harvard University after the war. From 1948 until returning to Washington in 1951 to become national director of the ADA he was executive director of its Massachusetts chapter.

Mr. Zalles, who had a private income, lived in Bethesda.

Survivors include two brothers, Robert and John, both of La Paz, and two sisters, Maria Zalles of New York City, and Leonor Freeland of Chevy Chase.