HYPOTHESIS: To verify the adequacy of duodenal segmentectomy after intestinal derotation in the treatment of primary adenocarcinoma of the third and fourth portions of the duodenum. DESIGN: A retrospective review of the surgical management of patients who underwent derotation of the third and fourth portions of the duodenum was undertaken to determine long-term outcome. SETTING: Departments of surgery in 3 university hospitals. PATIENTS: Between January 1, 1980, and December 31, 2000, 47 patients with primary adenocarcinoma of the third and fourth portions of the duodenum were surgically treated at 3 different institutions. MAIN OUTCOME MEASURES: Details of primary surgery were abstracted from clinical records of the original hospital referral. Postoperative clinical course and long-term outcome were evaluated by a review of the hospital records and follow-up. RESULTS: The results of a barium swallow test series was positive in 38 cases (80.8%) and esophagogastroduodenoscopy was primarily diagnostic in 30 patients (63.8%). In all cases duodenal segmentectomy was attempted. Twenty-two patients underwent palliative gastrojejunal bypass and in 9 patients pancreaticoduodenectomy was performed. In 16 cases duodenal segmentectomy was performed after intestinal derotation. Anastomoses were performed manually in all cases. Fifteen of the resected patients died of recurrent disease. A median (SD) disease-free survival of 36 (23.6) months (range, 6-85 months) was observed. The median (SD) overall survival was 37.5 (23.9) months (range, 11-85 months), the overall 5-year survival rate was 23% (11 patients), and the actuarial 5-year survival rate was 51% (24 patients). CONCLUSIONS: Duodenal segmentectomy associated with intestinal derotation was shown to be a straightforward, safe procedure for the treatment of the primary adenocarcinoma of the third and fourth portions of the duodenum. This surgical procedure should be preferred to pancreaticoduodenectomy because it is associated with negligible rates of morbidity and mortality, while allowing for satisfactory margin clearance and adequate lymphadenectomy.