Alfred M. Rivas, 79, who was a journeyman printer at The Washington Post for 10 years before retiring in 1976, died Monday at Georgetown University Hospital. He had cancer.

Mr. Rivas was a native of Sausalito, Calif. He served as an infantry sergeant with the Army in France during World War I. He was wounded in battle and received the Purple Heart.

He attended the University of Chicago and worked in Chicago-area steel mills during the night in order to support himself.

Mr. Rivas worked as a printer in St. Louis from 1930 to 1937, then started his own printing firm in Philadelphia. He went to work in the composing room of the Salisbury, Md., Times in 1950, an six years later became an advertising mark-up man with the Sunpapers in Baltimore.

Mr. Rivas joined The Washington Post in January 1966. He also gave a series of lectures on typography and printing at the University of Mexico in the early 1970s.

His wife, the former Mary Haislup, died in December 1978. His survivors include three sons, retired Air Force master sergeant Bernard T., of Newport News and Philadelphia, Robert, of Baltimore, and Air Force Technical Sergeant Alfredo T., of Andrews Air Force Base; a daughter, Nancy Rivas Bach of Glencoe, Ill., and nine grandchildren.