Howard J. LaFay, 58, a senior assistant editor of National Geographic magazine, died of cancer Tuesday at Georgetown University Hospital.

From the time he joined its staff in 1956, Mr. LaFay wrote 22 major articles for the magazine, covering assignments that took him from Leningrad to Trinidad and the DEW Line to Easter Island. He became a senior staff writer in 1976 and a senior assistant editor in 1980.

For his 1965 article, "Portugal at the Crossroads," he received Portugal's Antonio Ferro literary prize. His most recent article for the magazine was "Texas!" which appeared in last April's issue.

Mr. LaFay wrote about Andalusia in Spain and about Sir Winston Churchill's funeral. He wrote about the Vikings and the Maya. His enthusiasm as an amateur biblical scholar helped bring about a National Geographic article on archeological finds at the ancient Syrian city of Ebla.

Mr. LaFay was born in Jersey City, N.J. and was a 1944 graduate of Princeton University.

In World War II, he served for three years with the Marine Corps in the Pacific and was wounded on Okinawa, receiving the Purple Heart Medal. After studying for two years at the Sorbonne in Paris, he was recalled to active duty and served as a captain during the Korean conflict.

Before joining National Geographic, Mr. LaFay worked for Pathfinder News Magazine and its successor, Town Journal. He also wrote fiction.

Mr. LaFay is survived by his wife, Gloria, and four children, Kathy, Michael, Laura and Christopher, all of Falls Church.