Cancer of the small intestine represents less than two per cent of all the malignant tumors of the gastrointestinal tract. Because they are infrequent tumors, a review of a tumor registry was performed to analyze response to treatment of the disease and prognostic factors. A retrospective review of patients with primary cancer of the small intestine was performed using the Department of Defense Tumor Registry. The registry was accessed to determine stage, types of cancer, intervention, and patient outcomes. TNM staging and follow-up were available on 144 patients from 1970 to 1996. Median follow-up was 38.9 months. There were 92 (64%) males and 52 (38%) females. The median age was 55.7 years. The types of small intestinal cancer included 68 patients (47%) with adenocarcinoma, 41 patients (28%) with carcinoid, 18 patients (13%) with leiomyosarcoma, and 17 patients (12%) with lymphoma. The overall 5-year survival was 57 per cent and the median survival was 52 months. Survival of patients with adenocarcinoma was not dependent on location within the small bowel. Survival was best for early-stage tumors and when lesions could be completely resected.