Eleven cases of respiratory syncytial virus (RSV) infection occurred in acutely ill hospitalized adults over a 7-week period. Nosocomial illness was suspected in two patients. Because RSV can cause serious infections in immunocompromised adults with the potential for nosocomial spread, the following recommendations are indicated: (1) during the winter months, early recognition and diagnosis of RSV infections both in hospital staff and in patients should be encouraged; (2) infected hospital personnel should avoid patient contact when possible; (3) during outbreaks, careful attention must be paid to hand washing and gloving; and (4) a high level of vigilance for RSV infection should be maintained on units with immunocompromised patients. Increased awareness of the potential risks of RSV infection is needed on adult medical units.