Seventy-five patients with advanced abdominal carcinoid tumors (65 midgut, 10 others) have been examined retrospectively to evaluate the role of surgical treatment as a principle, irrespective of stage of disease. Eighteen of 52 patients (35%) exhibited the carcinoid syndrome. Two or more primaries were found in 39% of patients with midgut lesion, 81% of these patients had regional metastases, 5% of these patients had distant lymph node metastases, and 74% of the patients had liver secondaries. All patients underwent operation, an additional 34% of the patients had a further reoperation, 9% of the patients had a second reoperation, 3% of the patients had a third reoperation, and one patient (2%) had a fourth reoperation. Intraoperative debulking (liver excluded) was performed in 33% of the patients, and 48% of the patients had treatment (resection, hepatic artery ligation, embolization) directed at the liver. The postoperative mortality rate was 2% after the primary operation for midgut lesions. The median survival for midgut tumors was 92 months, compared to 40 months for other lesions (not significant). A significantly higher survival rate was revealed for those patients with midgut lesion who were undergoing intraabdominal debulking procedures (liver excluded); median survival was 139 months versus 69 months without debulking. For those patients with liver metastases, median survival after intervention was 216 months and 48 months without such treatment (p less than 0.001). It is concluded that resection of intraabdominal carcinoid tumor masses can be performed in a high proportion of patients. Despite the retrospective, uncontrolled nature of this study, the difference in survival probabilities in favor of aggressive surgical therapy is so marked that it is not unreasonable to conclude that surgery has played a role in prolonging life in these patients.