From 1976 to 1982, seven cases of free perforation of the sigmoid colon were treated at the Soroka University Hospital. None of the patients suffered any known underlying disease of the affected bowel such as malignancy, diverticulosis, ster-coral ulcer, colitis, or trauma. The only feature common to all seven patients was a long history of chronic constipation. All patients were treated surgically with no mortality and with minimal morbidity. We believe that severe untreated chronic constipation may, on rare occasions, cause free perforation of the sigmoid colon.