In the summer and fall of 1999 and in May 2000, ten outbreaks of salmonellosis were diagnosed in adult beef and dairy cows in Belgium. The main clinical sign was severe, often fatal diarrhoea. Catarrhal or haemorrhagic enteritis was the main necropsy finding. Infected cows excreted large numbers of Salmonella serotype Typhimurium. Six out of seven lysotyped Typhimurium strains belonged to lysotype DT104. In contrast with the Netherlands and the United Kingdom, this type of salmonellosis in adult cattle has not been reported in Belgium before.