One hundred seventy-one hyperplastic colonic polyps were examined and found to be less homogenous histologically than has been generally considered. For example, 13% exhibited adenomatous changes, 7.6% contained Paneth cells, and 3% had distinct stalks. They are at times pedunculated and relatively large; some cannot be distinguished grossly from small sessile polyps of other histological patterns and removal is required for proper identification. Other epithelial polyps of equivalent size were compared with the hyperplastic polyps to determine the frequency of the various types. Hyperplastic polyps comprised 43.5% of all surgically removed epithelial polyps of the colon measuring 5 mm or less.