T HE HISTORY of the Armed Forces' interest in influenza is long and generally well known. Certainly the World War I experience has been recalled often enough recently to indicate the concern at least that far back. During that period 1 in every 5 men in the Army contracted influenza, and roughly 25,000 died from its complications. This is nearly lhalf the number of battle deaths in the American Expeditionary Forces. The disease is still potentially important to the military as well as to the population at large. The modern history of the Armed Forces' activities directed toward the control of influenza dates from December 27, 1940. On that date Lt. Col. James Stevens Simmons, the late dean of the Harvard School of Public Health, wrote a letter recommending the establishment of a "Board for the Investigation and Control of Influenza and Other Epidemic Diseases in the Army." Within 15 days approval was granted by the War Department, and the board, with its formidable title, was established. This agency, now the Armed Forces Epidemiological Board, and its Commission on Influenza are still active. The continuity of the agency is apparent from the fact that two members of the early commission are now on the board, one as its president, and two others are now directors of other commissions. The major influenza control activities of tlhe three military departments could be classified in several different ways. I have chosen to consider them under four main headings: surveillance, investigations, vaccination, and medical care. I shall briefly describe the activities of each of these areas and report our experience so far.