PURPOSE: Because there are no significant differences of the clinical findings between the appendicitis and cecal diverticulitis, it is very difficult to make a correct diagnosis preoperatively and to choose a appropriate management intraoperatively. The purpose of this study is to investigate the clinical charateristics of right diveticulitis and to evaluate the appropriateness of surgical management. METHODS: We reviewed 45 cases of right colonic diverticulitis which underwent emergency operation under the impression of acute appendicitis during 10 years from January 1988 to December 1997. RESULTS: Of them, 38 cases were treated by diverticulectomy with appendectomy (Group I), and 7 cases were treated by resection (ileocecal resection or right hemicolectomy) (Group II). The male to female ratio was 4:1, and the mean age was 38.2 years. In Group I, all cases had a solitary inflamed cecal diverticulum. In group II, two cases had a solitary cecal diverticulitis, whereas five cases had multiple ones. Postoperative complications were found in 14 cases, but all of them were not significant. Postoperative Barium enema was performed in 22 cases of Group I, in two cases of Group II. In Group I, 8 cases had a residual diverticulum at postoperative Barium enema. In Group II, no residual diverticulum was shown. Follow-up study by Telephone was done at 16 cases, there were no symptomatic recurrences. CONCLUSIONS: In conclusion, when right colonic diverticulitis is found at the time of operation, surgical management is a safe treatment with low morbidity and low recurrence rate. Diverticulectomy with appendectomy is a safe surgical procedure for the uncomplicated diverticulitis. If diverticulitis is complicating, multiple or undistinguishable with malignancy, resection (ileocecal resection, right hemicolectomy) should be considered as a primary surgical treatment. Postoperative colon study is helpful, due to high incidence of residual diverticulum.