Diarrheal diseases are a major cause of childhood morbidity and mortality worldwide. Viruses are the leading cause of diarrhea, and rotavirus is the major cause of severe dehydrating diarrhea in both developed and developing countries. Children with viral gastroenteritis generally present with watery non-bloody diarrhea, often with vomiting and low grade fever. Disease is self-limited and treatment is simple--fluid and electrolyte replacement, preferably via the oral route, with early refeeding. While various adjunctive therapies, such as bismuth subsalicylate and oral immunoglobulins, appear promising, they cannot be routinely recommended at this time. Prevention is the key: by good personal hygiene--particularly good handwashing, by maintaining safe water supplies, and in the future, by an effective rotavirus vaccine.