THERE are few comprehensive studies recorded in the literature regarding the incidence of adenomas of the large intestine in children and in young people. Estimations of the incidence of adenomas vary with the type of material used for investigation. Thus different results are obtained if the adenomas are noted as a result of clinical symptoms directing attention to the large intestine than if they are noted in the large intestine at autopsy or in segments of the large intestine surgically resected. It is unlikely that many adenomas without accompanying manifest symptoms would be noted in young patients because few routine roentgenologic and proctoscopic examinations are done on this age group. If the material studied is obtained from autopsies or from surgical specimens, the incidence depends to a large extent on how carefully the specimen is examined. Small adenomas are easily overlooked when partially obscured by a mucosal fold.