Surgery for complications of colonic diverticulum was evaluated on the basis of a result of clinical experience for the 15 patients. 1) Average age was 48.9 years, and right-side oriented lesions were more often seen in younger patients. The men and women ratio was 1.5 to 1.0. 2) The reasons for surgery were disticulitis in 7 (46.7%), perforation in 3 (20.0%) and abscess and fistula formation in 2 (13.3%), respectively. 3) Complications on the left side were much more severe than those on the right side and also seen more often in older patients