Abstract 1. 1. A comparison of the incidence, symptoms and pathology of rectal carcinoids with those elsewhere in the intestinal tract is given. 2. 2. Although rectal carcinoids and their metastasis have the same microscopic pattern as other carcinoid tumors, the lack of argentaffinity is noted. 3. 3. The effects of increased blood levels of serotonin are discussed. 4. 4. Three cases of rectal carcinoids are presented, one proved, one probable with extensive metastasis to the liver, and the other in a ten year old boy with a large primary rectal tumor. None revealed any elevation in the serotonin levels. 5. 5. Radical resection of the rectum is urged for patients who have rectal carcinoids over 1 cm. in size or for any carcinoid tumors revealing ulceration, fixation or infiltration of the rectal wall.