Retired Navy Cdr. Edward Francis Scott, head of the science department at DuVal Senior High School in Prince Georges County, died Thursday at Bethesda Naval Hospital of a brain tumor. He was 66.

Born in Philadelphia, Cdr. Scott graduated from the Naval Academy in Annapolis in 1935. During his 26 years in the Navy, he was awarded the Presidential Unit Citation and commendation ribbon.

He continued his studies at George Washington University. By the time he retired from the Navy in 1960, he had earned a master's degree in education.

He taught physics and chemistry at DuVal Senior High School for 17 years, and became head of its science department. In 1963, he was voted science teacher of the year there.

He was to have retired from teaching on July 1.

Cdr. Scott is survived by his wife, Alice Jane, of the home in College Park; two sons, Edward Jr., of Upper Marlboro, and Jamie M. of College Park; a daughter, Ann, of Manchester, Mich.; two brothers, retired Army Col. James Scott, of Falls Church, and Charles Scott, of Hazelton, Pa., and five grandchildren.

The family suggests that expressions of sympathy may be in the form of contributions to the American Cancer Society in his name.