BASAL cell carcinoma of the anus is a lesion that has been diagnosed and reported in the literature only 12 times. Basal cell carcinomas are classically described as occurring on the skin of the face and head superior to a line drawn posteriorly from the angles of the mouth. Experience teaches us that basal cell carcinoma may occur anywhere on the body, on the covered as well as on the exposed surfaces. Its occurrence in the anal area is most rare, and so a 13th case is published here. The previously reported cases are summarized in the accompanying Table. REPORT OF CASE A 65-year-old white man (Case No. A 14755) was first seen at the Barnard Free Skin and Cancer Hospital on July 25, 1952, with the chief complaint of a "sore on his rectum." Three years prior to his admission to the outpatient department of this hospital, he had