Abstract: OBJECTIVE To investigate the main characteristics and possible causes for the outbreaks of duodenoscopy associated infections. METHODS A systematic review was conducted. The key words of "duodenoscopy", "infection" and "outbreak" were selected to search the published articles in CNKI, Wanfang and PubMed. The characteristics and possible causes for the outbreaks of duodenoscopy associated infections were comprehensively analyzed. RESULTS According to the inclusion and exclusion criteria, 19 articles were included. Totally 9 of 19 articles were reported in America, involving 204 patients. Totally 12 articles reported positive culture, mostly in endoscopic cavity and forceps placement. Incomplete cleaning and disinfection were the main causes for the outbreaks, including the design defects of duodenoscopy, incomplete cleaning, unreasonable disinfection and unqualified storage and monitoring, etc. CONCLUSION Incomplete cleaning and disinfection are the main causes for outbreaks of duodenoscopy associated infections. Effective measure should be taken, especially paying attention to the cleaning and disinfection process of duodenoscopy, so as to minimize the occurrence of outbreaks.