Clostridium perfiringens may cause myonecrosis (i.e. gas gangrene), acute food poisoning or necrotic enteritis (e.g. enteritis necroticans or Pig Bel). We describe a case of enteritis necroticans in a 33 year old man with acute myeloid leukaemia. He presented with an acute abdomen, diarrhoea and pancytopaenia and extensive accumulation of gas in the intrahepatic and extrahepatic portal veins. Despite urgent resuscitation he died shortly after arrival in the Intensive Care Unit. Treatment of enteritis necroticans requires urgent surgery to remove dead bowel and in adults intravenous penicillin (1g 2-hourly) and metronidazole (500 mg 8-hourly) or clindamycin (600 mg 6-hourly). While antibiotics may also reduce toxin formation, beta toxoid has not been found to be of benefit in established disease.