The past few years have seen important developments in understanding the epidemiological and virological characteristics of rotaviruses, and rapid progress has been made in rotavirus vaccine development, but further challenges remain before a vaccine is introduced into widespread use. The licensure of the first rotavirus vaccine, a tetravalent rhesus-based rotavirus vaccine, in the United States in 1998, marked a significant advance in preventing the morbidity associated with rotavirus diarrhea. The association between the tetravalent rhesus-based rotavirus vaccine and intussusception has created significant hurdles as well as new opportunities to study the pathogenesis of rotavirus and rotavirus vaccine infection. Several other rotavirus vaccine candidates are in late stages of development, and results from trials have been encouraging.