Objective: To investigate the risk factors associated with the disease free survival (DFS) for primary duodenal adenocarcinoma patients undergoing radical resection. Methods: The clinicopathological data of 101 primary duodenal adenocarcinoma patients who underwent radical resection from January 2001 to October 2014 were retrospectively reviewed. Using SPSS 13.0 software, the survival curve was drawn by Kaplan-Meier method, and the survival rates were analyzed by Log-rank test.COX regression model was used to identify independent risk factors. Results: Among 101 patients, the main clinical manifestation were upper abdomen discomfort, abdominal pain, jaundice, gastrointestinal obstruction, hemorrhage, emaciation and so on. A total of 87 patients had the tumor located at the descending part of the duodenum. All the 101 patients underwent radical resection, and 85 patients received pancreatoduodenectomy while 16 patients underwent segmental resection. The median disease free survival time was 26 months and the postoperative 1, 3, 5 year DFS rate were 79.7%, 60.3% and 53.6%, respectively. The univariate analyses identified elevated preoperative CEA and CA19-9 level, T stage, lymph node state, vascular invasion and perineural invasion predicting a worse DFS(P<0.05). On multivariate analysis, positive lymph node state was an independent risk factor for DFS (RR=5.394, 95% CI: 1.624-17.913). Conclusion: Radical resection is the best therapeutic method for primary duodenal adenocarcinoma; the positive lymph node state is the independent risk factor affecting the disease free survival of patients after radical resection.