Richard Coke Marshall, III, 73, a Washington attorney and businessman from 1935 until 1969, when he retired to Beaufort, S.C., died at his home there Friday. He had had a stroke recently.

Mr. Marshall was born at Fort Monroe, Va., and graduated from the Virginia Military Institute. He earned his law degree at Harvard University and then practiced briefly in New York City.

In 1935, he moved to Washington and established a private practice. He also was an officer or director of a number of corporations. He was a member of the firm of Hill & Marshall at the time of his retirement.

During World War II, Mr. Marshall served in the Army in the Southwest Pacific and in the Pentagon. He left the service as a lieutenant colonel.

He was a Junior Warden of Christ Church here and a member of the board of trustees of the Holton Arms School. He also was a member of the Chevy Chase and Army-Navy clubs and the Harvard Club of New York City.He was a member of the Society of the Cincinnati in Virginia.

Mr. Marshall's survivors include his wife, Florence Beale Marshall of Beaufort; three daughters, Mary M. Bowen of Kensington, Florence M. Mallory of Bethesda, and Sophie M. Nicholson of Ford Ord, Calif.; one son, Richard C. IV, of Richmond, and eight grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the VMI Foundation, Lexington, Va.