A 5-year retrospective case review and 6-month clinical observation, in a teaching and general hospital in Bangkok, Thailand, show that colonic diverticular disease is not so common as in the West and has many distinctive features. Solitary cecal diverticula are at least five times more common, accounting for about one-fourth of all diverticula of the large bowel, and show definite male preponderance and occur in younger patients. Their congenital origin is supported by the lack of association with social classes, by the finding of structural relationship with the appendix in one of the patients, and by the presence of the muscular coat. On the other hand, multiple colonic diverticulosis is essentially a disease of those above the age of 40 years and shows slight female preponderance. The diverticula appear segmental and need not originate in the sigmoid colon first. Almost all multiple diverticula show radiologic features of simple massed diverticulosis and seem to be associated with higher social classes. The differences in the pattern of diverticular disease in this series and in the West cannot be readily explained on the basis of the difference in dietary habit or psychologic stress.