Virtually all children experience rotavirus (Rv) infection before school entry. In the United States and other temperate countries, Rv disease peaks in the winter and during this time is responsible for the majority of episodes of diarrhea in infants and young children. Data collected by the Centers for Disease Control and Prevention from 1979 through 1992 indicate that approximately 50 000 hospitalizations attributable to Rv occur annually in the United States, a number that approximates about 1 in 78 children being hospitalized with Rv diarrhea by 5 years of age. RotaShield (Wyeth-Lederle Vaccines and Pediatrics, Philadelphia, PA) was licensed by the Food and Drug Administration on August 31, 1998, for oral administration to infants at 2, 4, and 6 months of age. The rationale for using Rv immunization for prevention or modification of Rv disease is based on several considerations. First, the rate of illness attributable to Rv among children is comparable in industrialized and developing countries, which indicates that improved public sanitation is unlikely to decrease the incidence of disease. Second, although implementation of oral rehydration programs to prevent dehydration has improved in the United States, widespread use is inadequate to prevent significant morbidity. Third, trials of rhesus rotavirus-tetravalent (Rv) vaccine in the United States, Finland, and Venezuela show efficacy rates of approximately 80% for prevention of severe illness and 48% to 68% against Rv- induced diarrheal episodes. These results are similar to the protection observed after natural Rv infection, which also confers better protection against subsequent episodes of severe disease than against mild illness. This statement provides recommendations regarding the use of Rv vaccine in infants in the United States.