Sixty-five patients seen at the Massachusetts General Hospital between 1951 and 1974 with carcinoid tumors of the gastrointestinal tract are reviewed. Sixty-two patients were operated upon, and only one carcinoid was discovered for the first time at autopsy. Although corrected actual five and ten year survival rates of more than 60% were attained, only one of 15 patients was alive five years after the discovery of liver metastases. Patients less than 60 years of age, with tumors of less than 0.5 centimeter in diameter and with no history of weight loss, survived best. Most rectal and appendiceal carcinoids were small, and there were no deaths in patients who had undergone local resection. Only 33% of the patients with small intestinal carcinoids survived for five years; none survived for more than one year after diagnosis of the carcinoid syndrome was made. All colonic carcinoids had metastasized by the time the operation was performed. Carcinoids of less than 0.5 centimeter in diameter located anywhere in the gastrointestinal tract can be managed by simple local resection. Tumors 1 centimeter in diameter warrant consideration of a more extensive operation. A radical excision usually is required for tumors of more than 2 centimeters in diameter, even in the presence of metastatic disease.