Robert B. Jefferson, 78, assistant director of admissions at Howard University until his retirement in 1957, died Tuesday at Washington Hospital Center. He had suffered from leukemia.

Mr. Jefferson, also a visiting lecturer in education at Howard, began his 46-year career in education as a teacher at St. Augustine's College in Raleigh, N.C.

He then served as dean at Delaware State College and at Alcorn Agricultural and Mechanical Collegeat Lorman, Miss. He also had been head of the education department at Prairie View Agricultural and Mechanical College in Texas.

He was a veteran of World War I.

Mr. Jefferson, who moved to Washington in 1944, was born in Athens, Ga. He earned a bachelor's degree and a master's degree from Columbia University in New York City and a degree in philosophy from the Univeristy of Chicago. He also had done graduate work at the University of Pennsylvania.

He had been a member of the NAACP and the Pigskin Club, the Frontiers and the Bachelor-Benedicts here. He attended All Souls Memorial Episcopal Church.

Survivors include his wife, Nell C., of the home in Washington; two sisters, Eleanor Usher, of Atlanta, and Geneba J. Cassey, of Detroit, and two brothers, Herman H., of Columbus, Ohio, and Dr. Richard H., of Atlanta.