&NA;In a series of 1,002 cases of primary colorectal adenocarcinomas diagnosed during a ten‐year period there were 62 (6.2 per cent) patients who had two or more primary colorectal adenocarcinomas. Most of the tumors were more than 5 cm away from each other: 27 carcinomas were separated by 6‐10 cm, 16 were separated by 11‐20 cm, and 12 were separated by more than 20 cm. It is concluded that the incidence of synchronous carcinomas of the colon is sufficiently high to warrant a search by both surgeon and endoscopist for additional tumors some distance from the initial lesion.