The angiographic findings of five small intestinal and two colonic carcinoids are described and illustrated, together with a review of the pertinent literature. It is pointed out that the demonstration of a complex of angiographic findings related to the primary site, mesentery, and liver is highly specific. It helps in the preoperative diagnosis as well as in the localization and stage of development of the gastrointestinal carcinoid. The triad of findings is composed of: (a) faint to moderate staining at the primary site; (b) narrowing, obstruction of the distal mesenteric arcade, cluster of irregular kinked vessels, and encasement in the more central areas of mesentery; and (c) hypervascular liver metastasis. The colonic lesions examined are unique in the literature, and exhibited angiographic findings similar to the small bowel carcinoids.