Medical records of 99 hospitalized pediatric patients whose respiratory viral cultures yielded influenza type A or B during the winter of 1988/1989 were reviewed. We compared the records of patients considered to be at high risk (n = 43) with those of patients considered to be at low risk (n = 56) to determine differences in morbidity and mortality and if vaccination was warranted. Sixty-six percent of high-risk patients had chronic pulmonary disease. Forty-four percent of the high-risk and 11% of the low-risk patients were hospitalized for 14 or more days. Nosocomial influenza infections were identified in 14% of the high-risk and 4% of the low-risk patients. Four of the high-risk patients and only one of the low-risk patients were intubated. Of the three deaths, two occurred in the high-risk group. None of the high-risk patients who experienced significant morbidity had been immunized. We need to immunize high-risk patients, particularly high-risk pulmonary patients.