BACKGROUND Adverse events are under-appreciated negative consequences that are significant clinical problems for patients undergoing anti-MDR-TB treatment due to longer duration of treatment and more need for concurrent use of multiple second-line drugs. The aim of this study was to determine the incidence of adverse events and their impact on MDR-TB therapy and treatment outcome, and to identify possible drug-event pairs in China. MATERIAL AND METHODS An ambispective cohort study was conducted based on hospital medical records, which included a retrospective study that enrolled 751 MDR-TB patients receiving standardized regimen between May 2009 and July 2013, and a follow-up investigation of treatment outcome conducted in December 2016 in China. Adverse events were determined according to laboratory results or clinical criteria. Cox's proportional hazards regression models were used for evaluating associations. RESULTS There were 681(90.7%) patients experienced at least 1 type of adverse event and 55.2% of them required a changed MDR-TB treatment; 51(6.8%) patients required permanent discontinuation of the offending drug due to adverse events. The occurrence of adverse events was associated with poor treatment outcome (adjusted hazard ratio, 1.54; 95% CI 1.21, 1.87). A total of 10 different drug-event pairs were identified. CONCLUSIONS Adverse events occurred commonly during MDR-TB treatment in China, and often resulted in MDR-TB treatment change. The occurrence of adverse events affected MDR-TB poor outcome after treatment.