Col. Ralph M. Thompson 76, a retired officer of the Air Force Medical Corps who was a decorated veteran of World War II, died Nov. 25 at the Veterans Administration hospital in Martinsburg, W.Va. He had cancer.

As commander of the 104th Evacuation Hospital, Col. Thompson participated in the landing at Omaha Beach in Normandy during the invasion of Europe. He commanded the unit as a component of the 1st and later 3rd armies and treated the wounded in Luxembourg during the Battle of the Bulge. a

His decorations included the Legion of Merit, the Bronze Star Medal and a Purple Heart. The 104th received a unit citation in May 1945.

From 1951 until retiring from active duty four years later, Col. Thompson directed Air Force activities at the Armed Forces Institute of Pathology in Washington.

Following his retirement, he continued to live in Alexandria and became associated with clinical and pathological laboratories at Alexandria, Circle Terrace, and Jefferson Memorial hospitals there. He retired a second time in 1968.

He was a fellow of the College of American Pathologists and belonged to the District of Columbia, Virginia State and Alexandria medical societies.

Col. Thompson was a native of Omaha, Neb., and earned bachelor's and medical degrees at the University of Nebraska. He received a commission in the Army Medical Corps in 1929, and graduated from the Army Postgraduate Medical School and the Army Medical Field Service School the following year.

He is survived by his wife, Jacqueline L. of Alexandria; a son, Frederic L. of Springfield and a brother, Dr. Lynn M., of Arkansas.