To evaluate long-term survival of patients with gastrointestinal carcinoid tumors and to assess factors that may influence prognosis, 154 patients (49% females, 51% males), median age 62 years (range 12-84 years) treated at our institution during 1972-1982 have been followed long term. Tumor location included the foregut (7%), midgut (62%), and hindgut (30%). Ninety-five percent of the patients underwent surgical or endoscopic excision of the primary tumor, with overall operative mortality and postoperative morbidity rates of 2. 6% and 11%, respectively. At follow-up, 60 patients (39%) were alive (median follow-up 18 years; range 1-26 years). The main causes of death included carcinoid tumor burden (32%), unrelated causes (45%), other malignancy (19%), and unknown causes (4%). Observed overall 5- and 10-year survivals were 69% and 53%, respectively. Survival was not related to gender or symptoms at presentation. However, age, embryologic origin, tumor size, depth of invasion, nodal status, and stage of disease proved to be of statistical significance (log-rank). In a multivariate Cox' model, only older age (> 62 years) [P = 0. 001, odds ratio (OR) = 3.4) and embryologic origin (midgut versus foregut) (P = 0.045, OR = 0.45) provided independent prognostic power when death from any cause was taken as the end-point. This study confirms that patient's age and the site of the primary tumor have prognostic significance. Carcinoid tumors are neuroendocrine tumors with a relatively good prognosis, and long-term survival is possible despite advanced stages of disease.