A regression model for the nonepidemic level of influenza-like syndrome has been estimated from the 55,200 cases collected between October 1984 and August 1988 using the French Communicable Diseases Computer Network. The start of a major epidemic in 1988-89 was detected early. The size of the epidemic, for the entire country, was estimated at approximately 4.3 million cases. The excess cost of sick-leave, among those of working age, was estimated at $86 million.