Objective: To analyze the occurrence and preventive measure of alimentary tract fistula associated with severe acute pancreatitis (SAP). Methods: The clinical data of 23 SAP patients complicated with alimentary tract fistula admitted between Jan 2000 to Jan 2012 were reviewed. The location and time of onset of the digestive tract fistula, and extent and features of the pancreatic lesions of these patients as well as the relationship between the occurrence of digestive tract fistula and drainage tube placement were analyzed. Results: Of the entire group of 23 patients, 11 cases were colonic fistulas (47.8%), 7 cases were duodenal fistulas (30.4%), 4 cases were small bowel fistulas (17.4%), and 1 case was gastric fistula (4.3%). The alimentary tract fistulas generally occurred within the first or second week after operation for SAP. The extent of pancreatitis damage in these patients was relatively large, which usually affected the head of the pancreas, duodenum and colon. The occurrence of digestive tract fistula in 16 of these cases was associated with the drainage tube placement. Conclusion: Alimentary tract fistulas in SAP are related to anatomic factors, extra-pancreatic inflammation and surgical injury as well as the natural course of SAP. Prevention of alimentary tract fistulas should be integrated into the overall treatment of SAP.