Fecal shedding of rotaviruses by infants and children without gastrointestinal symptoms has recently been recognized, but little is known about the duration or frequency of virus shedding in such patients. We therefore evaluated rotavirus shedding by 16 infants and children during the course of their prolonged hospitalizations. Repeated fecal specimens were obtained from these patients and examined for the presence of rotavirus by means of immunoassay, electron microscopy and polyacrylamide gel electrophoresis. Asymptomatic rotavirus shedding was observed in each of the 16 patients, and more than 1 episode of virus excretion was detected in 15 of these. Electropherotype analysis indicated that some of these episodes were probably the result of reinfection with different strains of rotavirus. Asymptomatic shedding may be important in transmission of rotaviruses. Its role should be taken into consideration in future investigations of the epidemiology and control of this nosocomial pathogen.