An unusual case of a 44 year old woman who developed a nonspecific ulcer of the sigmoid colon is reported herein. She presented with lower abdominal pain and fever and colonoscopy revealed a large, sigmoid colon ulcer with normal surrounding mucosa and a well-defined margin. A temporary sigmoidostomy was done to decompress the bowel content and, after the abdominal pain and fever had subsided, the involved segment with an ulcer of 6.1 X 2.5 cm was resected. Her postoperative course was uneventful and she has remained well since.