To discuss indications for local excision of adenocarcinoma of the low rectum, two different series of patients were analysed. Series I consisted of 60 patients treated by local excision from 1969 to 1985 in whom local recurrence developed. Series II consisted of 59 patients who underwent resection for non high grade tumors less than or equal to 3.5 cm from 1980 to 1990 in whom lymph node spread was studied. A distinction is made between tumors which are obvious cancers and malignant polyps, and the discussion of indications for local excision is orientated to the former. The results of local excision have been disappointing but a number of compromise selections for local excision have been necessary. Endorectal ultrasound has emerged as the most important method of assessing the depth of invasion of the tumor. Stratifying the depth of the tumor is at present the most important prognostic indicator for lymph node metastasis and local recurrence in non high grade tumors. If the muscle layer is invaded by tumor, local metastasis will occur in 17% of patients. It is likely that only tumors involving superficial layers of muscle are suitable for local excision, but this needs further study. Mucinous carcinomas and the presence of lymphatic invasion are contra-indications to local excision. The shape and size of tumors are not independent prognostic indicators. The techniques available for local excision alter the indications. Salvage operations for recurrence after local excision have proved disappointing.