CECAL diverticulitis is a definite yet relatively infrequent clinical entity. In the differential diagnosis of pain in the right lower quadrant, the possibility of diverticulitis of the cecum is not often considered. From 1912, when the first case of diverticulitis of the cecum appeared to have been reported, to April of 1950, there had been only 118 reported cases. To this number the present authors are adding four cases. The literature gives evidence of a belief that the delineation between the lower portion of the ascending colon and the upper part of the cecum is not well defined. Therefore, there is undoubtedly some incidence of diverticulitis of the ascending colon included in these reports on diverticulitis of the cecum. We have attempted in this paper to separate the former from true cecal diverticulitis. A diverticulum, as defined by Dorland,1is a pouch or pocket leading off from a main