Outbreaks of influenza A virus infection can cause substantial morbidity and mortality among residents of nursing homes. Surveillance for the 1991-92 influenza season indicates that the dominant circulating viruses are influenza A (1), for which amantadine hydrochloride is effective for prevention and treatment (2). This report describes the use of amantadine as an adjunct to influenza vaccine for controlling an influenza A(H3N2) outbreak that occurred in a Washington nursing home during the 1989-90 influenza season.