The present study was conducted to evaluate the current status of rectal carcinoids from multiple systemic aspects, based on extensive information provided by 1271 cases cited in 465 international articles published since 1912. Each case report was carefully read, computerized, and analyzed by the gut-pancreatic endocrinoma analysis system (Niigata Registry). To avoid case duplication, cases without individual identification, such as the age and sex of the patient, and those with identical clinical and laboratory data and institutes of source, were excluded. Where appropriate, selected cases from an overall gastrointestinal (GI) series consisting of 4461 cases similarly documented in the same Registry were referred to for comparison. The representative characteristics of rectal carcinoids consisted of a male preponderance, small-sized tumors of 10 mm or less at detection, predominant submucosal invasion with a relatively high incidence of metastases, a high incidence of hematogenous spread, a predominant histology of the B-type growth pattern, a low rate of silver reactivity, the infrequent association of carcinoid syndrome, and a relatively high rate of mortality within 5 years after removal of the lesions.