Denmark has in recent years experienced a rise in the number of bacterial gastrointestinal infections. We have reviewed patients hospitalized with culture confirmed bacterial gastroenteritis in Roskilde County during 1991-1993. Two hundred and seven patients were included, 68 were children (<15 years). The microorganism isolated was Salmonella in 61% of the cases, Campylobacter in 20% and Yersinia enterocolitica in 13%. Ninety-three percent of the patients had diarrhoea, 74% had fever (>38°C), and 66% abdominal pain. Blood in the stools was most frequent in patients infected with Campylobacter. Leucocytosis was rare. Twenty-four patients had bacteraemia. Reactive arthritis occurred in 4.8%. Three patients died, all infected with zoonotic Salmonella types. Three stool cultures were made for 115 patients, and all three cultures were positive in 73% of these patients. Bacterial gastroenteritis requiring hospitalization in Roskilde County, 1991-1993 affected mainly children and young adults. Infections due to zoonotic Salmonella types were more severe than Campylobacter and Yersinia enterocolitica gastroenteritis. It seems necessary to collect at least three stool cultures to secure a bacteriological diagnosis.