A 38 year old lady with a previous history of an ovarian cyst, presented with a one week history of fever, diarrhoea and intense localized pain in the left iliac fossa. Laparotomy revealed a left tuboovarian abscess with adherent bowels. Pus from the ruptured cyst grew Salmonella enteritidis. Histologically the cyst wall showed haemorrhagic and degenerate endometriotic features. Recovery was uneventful with cefotaxime and metronidazole.