Out of 1, 124 cases of diverticular disease of the colon seen during the past 15 years, 27 cases (2.4%) of diverticulitis and 44 cases (3.9%) of diverticular hemorrhage were found. The incidence of diverticulitis was more frequent in the both-sides colon type, and also in the multiple form having 10 or more diverticula. The average age was higher in diverticulitis of the sigmoid colon (57.8 years) than in diverticulitis of the right-side colon (47.9 years). Twenty-two cases (81%) of these patients were recovered by medical treatment, and in 5 cases (19%) of these, elective colectomy was carried out. On the other hand, the incidence of diverticular hemorrhage was more frequent in patients over 70 years old, and also in the multiple form having 10 or more diverticula. Though anemia was seen in 1 1 (25%) of 44 cases, all patients were recovered by medical management.Namely, diverticulitis of the right-side colon is more frequent in middle age, and both diverticulitis of the sigmoid colon and diverticular hemorrhageare morefrequent in old age.