ABSTRACT BACKGROUND: Anastomotic leakage is a morbid and potentially fatal complication of colorectal surgery. Determination of peri-operative risk factors for colorectal anastomosis leak helps to identify patients requiring increased postoperative surveillance. METHODS: Institution based retrospective study was done to determine colorectal anastomosis leak rate and risk factors associated with it at a teaching hospital in Addis Ababa Ethiopia. Patients operated from January 2013 to December 2017 G.C were included. Univariate analysis followed by a multivariate logistic regression model was used to determine the influence of patient factors and operative events on postoperative anastomotic leakage. RESULTS: Inclusion criteria were met by 221 patients. Mean age of patients was 46.44(SD=19.1) with range of 1 to 85 years. Male accounted to 166 (74.8%) of the patients. Anastomotic leakage occurred in 12 (5.2%) of the patients. Mean time to diagnosis was 9.55 days (95% CI, 7.2-11.8) after surgery. Univariate analyses showed high preoperative level of creatinine, ASA score III and IV, emergency operation, operative time more than three hours, and malignant diseases were associated with colorectal anastomosis leak. Multivariate logistic regression model failed to show an association. Colorectal anastomosis leak increased the inpatient mortality rate by 50%. Median length of hospitalization in colorectal anastomosis leak group was 27.5 days, versus 7 days in patients without leak.CONCLUSION: Colorectal anastomosis leak remains common problem after colorectal surgery resulting significant post-operative mortality and morbidity. Key words: Anastomosis, Anastomosis Leak, Risk factors