Ada E. Murphy, 78, a nurse who was a retired U.S. Health and Human Services official and colonel in the Army Reserve, died of cancer July 3 at Walter Reed Army Medical Center. She lived in Washington.

Miss Murphy, who was born in Pennsylvania, came to Washington in 1937. She graduated from Roosevelt High School in 1938 and from the Providence Hospital nursing school in 1941. She later graduated from Catholic University.

She served on active duty as an Army nurse during World War II and the Korean War and retired from the reserves in 1990.

Miss Murphy worked for the Visiting Nurses Association from 1948 to 1950. She became a nurse in the federal employee health division of the Department of Health, Education and Welfare in 1954 and retired in 1990 as the division chief in what had become the Department of Health of Human Services.

In 1962, she was "Nurse of the Year" in the Military District of Washington. She was a member of the American Nurses Association, the American Association of Industrial Nurses and the Sigma Theta Tau honorary nursing society. She was a certified occupational health nurse.

Miss Murphy was a member of Shrine of the Most Blessed Sacrament Catholic Church and its sodality. She also belonged to the Christ Child Society.

Survivors include a sister, Harriet M. Murphy, and a brother, George W. Murphy Jr., both of Washington.