PURPOSE: Emergency colorectal surgery has a high risk of mortality and morbidity because of incomplete bowel preparation, bacterial proliferation, and contamination. In this study, we investigated the outcomes and the risk factors affecting mortality in patients who had undergone emergency surgery for the treatment of various colorectal diseases. METHODS: This study is a retrospective analysis of prospectively collected data to survey the clinical results for patients who had undergone emergency colorectal surgery from January 2014 to December 2014. We analyzed various clinicopathologic factors, which were divided into 3 categories: preoperative, intraoperative, and postoperative. RESULTS: A total of 50 patients had undergone emergency colorectal surgery during the time period covered by this study. Among them, 10 patients (20%) died during the postoperative period. A simple linear regression analysis showed that the risk factors for mortality were old age, preoperative hypotension, and a high American Society of Anesthesiologist (ASA) score. Moreover, a multiple linear regression analysis showed a high ASA score and preoperative hypotension to be independent risk factors. CONCLUSION: In this study, emergency colorectal surgery showed a relatively high mortality rate. Furthermore, the independent risk factors for mortality were preoperative hypotension and high ASA score; thus, patients with these characteristics need to be evaluated more carefully and receive better care if the mortality rate is to be reduced.