During an outbreak of Salmonella typhimurium food poisoning in September 1983, in Sydney, 10 affected subjects were admitted to the same hospital. On admission to hospital, all patients were severely dehydrated; two patients developed acute tubular necrosis, while a third patient had myopericarditis. Bacteraemia was confirmed in two patients, in one of whom no organisms were isolated from stool cultures. Antibiotic agents were administered to all patients, because of the unusually severe nature of the infection. This outbreak illustrates that salmonella gastroenteritis, although usually fairly mild and self-limiting, can be a virulent disease resulting in serious complications. Appropriate management should include careful initial assessment of suspected cases, vigorous correction of fluid and electrolyte disturbances, and judicious use of antibiotic agents when bacteraemia or severe toxaemic features are present.