Background: Gastrointestinal stromal tumors (GISTs) occur rarely in the duodenum. Because of their low incidence, data on long-term survival and prognostic factors are limited. The aims of this study were to present the authors' experiences in the diagnosis and treatment of this disease and to evaluate long-term surgical outcomes., Methods: Clinical data from 22 consecutive patients with duodenal GISTs surgically managed from May 1999 to August 2011 were retrospectively studied. A pooled analysis was done by systematically reviewing other case series reported in the English literature. Recurrence-free survival and independent predictors of adverse outcomes were analyzed using the Kaplan-Meier method and multivariate Cox regression., Results: Duodenal GISTs had a mild male predominance (68.2%), occurring primarily in older adults (median age, 58 years), with a frequency of 7.49% among all GISTs. Clinical presentations were nonspecific, with gastrointestinal bleeding and abdominal pain or discomfort being the most common symptoms. The tumors were located mainly in the second portion of the duodenum, in 14 patients (63.6%), with a median size of 3.75 cm (range, 1.4 to 14). All patients underwent curative surgical resection, including 9 pancreaticoduodenectomy, 3 segmental duodenectomy, and 10 local resection. Eighteen patients were alive without evidence of recurrence after a median follow-up period of 67.5 months (range, 3 to 118). The 1-year, 2-year, and 3-year rates of recurrence-free survival were 95%, 89.5%, and 86.7%, respectively. Kaplan-Meier analysis and log-rank tests showed that surgical pattern, mitosis, and risk grade were significantly associated with recurrence-free survival (P < .05 for all). However, only high mitosis was a significant predictive factor for adverse outcomes on multivariate analysis (hazard ratio, 16.414; 95% confidence interval, 1.914 to 140.756; P = .011)., Conclusions: Duodenal GIST is an unusual neoplasm with favorable survival after curative resection. Mitotic activity was more influential than tumor size and risk grade in predicting adverse outcomes. All patients with duodenal GISTs require long-term follow-up, because late relapse can occur even if the tumor has low malignant potential., (Copyright © 2013 Elsevier Inc. All rights reserved.)