PURPOSE: Tumors of the small bowel are rare, accounting for about 3-6% of all gastrointestinal neoplasms, though they cover more than 90% of the intestinal surface. However, diagnosis and treatment are difficult and present an ongoing challenge for both gastrointestinal surgeons and gastroenterologists. The aim of this study was to investigate the clinical features of small bowel tumors. METHODS: Between November 1994 and November 2007, 81 patients underwent treatments for primary tumors in the jejuno-ileal region at the Department of Surgery, Kangnam St. Mary's Hospital, the Catholic University of Korea. A retrospective review of the patients' characteristics and variable tumor factors was performed. RESULTS: The mean age of the patients was 53.2 years with 48 men and 33 women. The most common symptom was abdominal pain (59.3%), followed by bleeding (22.2%) and an abdominal mass (6.2%). We found that the patients with ileal tumors complained mainly of abdominal pain (72.9%) whereas the patients with jejunal tumors presented with gastrointestinal bleeding (36.4%) (P = 0.048). Seventy-six of the 81 patients (93.8%) had malignant tumors, including 40 (49.4%) gastrointestinal stromal tumors, 26 (32.1%) lymphomas and 5 (6.2%) adenocarcinomas. No postoperative mortalities were observed. The overall 5-year survival rate of the patients with malignant small bowel tumors was 31.8%. CONCLUSION: Because the clinical features of a primary tumor of the small bowel are obscure and its diagnosis is difficult, maintaining a high degree of suspicion and recognizing the possibility of a primary small bowel tumor are important.