Among 24 patients, 6 had gastric epithelioid leiomyosarcoma, pulmonary chondroma, and functioning extra-adrenal paraganglioma, and the remaining 18 had two of the three tumors. This unusual triad of tumors almost certainly constitutes a specific entity because the coincidental occurrence of the three tumors is improbable, because the tumor multicentricity in the organs or system affected is unusual, because the tumors appeared at an age when neoplasms are uncommon, and because of the predilection of the association for young women. If two of the neoplasms are present, a presumptive diagnosis of the "triad" can be made, particularly if age and sex factors are supportive. Because two components of the "triad" are potentially lethal, it is important that patients less than 35 years of age who have any one of the three tumors be examined periodically in search of the others.