Alexander Firfer, 59, an economist who had been head of Agency for International Development missions to several Latin American countries, died of cancer Wednesday at his home in Bethesda.

He had retired in June as special assistant for appropriate technology in the office of the science adviser of AID, and had received the agency's Distinguished Career Service Award.

Mr. Firfer joined AID in 1962, and was chief of its mission to Boliva in LaPaz for three years. He then became director of the AID mission to the Dominican Republic for four years.

He spent a year in Vietnam as deputy director of Military Region I of the AID mission to that country. During 1970-75, he was chief of the AID mission to Panama. He then served two years as a member of a special interagency group to work on negotations of the Panama Canal treaties.

Mr. Firfer was born in Paterson, N.J. He graduated in 1940 from New York University and took graduate work at Columbia and American universities.

During World War II, he worked in Washington in the Office of Price Administration and the Small Defense Plants Administration. After teaching economics in 1946-47 at North Caroline State College in Raleigh, he returned to Washington to work for the Federal Communications Commission.

Mr. Firfer was employed by the Commonwealth of Puerto Rico as a consultant to its "Operation Bootstrap" development program during 1954-58. He then was a technical expert for the United Nations in Caracas, Venezuela, for four years.

He is survived by his wife, Marina, of the home.