The clinical and epidemiological aspects of rotavirus diarrhoea were studied in hospitalized children with acute diarrhoea in Lusaka, Zambia. Two hundred and fifty-six (24.0%) of 1069 children admitted to the study were shedding rotavirus. The rotavirus-positive rate was highest in children less than 1 year of age (37.0%) and it was also high in those less than 6 months old. Rotavirus diarrhoea was seen throughout the year with a higher rotavirus-positive rate in the dry season. In rotavirus-positive diarrhoea patients, more children were dehydrated (82.4%) than in the rotavirus-negative group (56.2%). Rotavirus infection was more common in the children with normal nutritional status (27.6%, 162/588) than in those with malnutrition (19.3%, 93/482). The associated case fatality rate in the rotavirus-positive group was 6.4%, significantly less than in the rotavirus-negative group (OR 0.44, 95% CI 0.24-0.79), and mortality cases were seen only in children less than 2 years old.