Background: Surgical site infections are global healthcare problems. Although surgical site infections are preventable, they still cause significant morbidity, high death rates, and financial stress on national budgets and individual patients. Inappropriate uses of surgical antimicrobial prophylaxis are increasing and worsening patients' quality of life. This study determined the incidence and risk factors of surgical site infections. Methods: Institution-based retrospective cross-sectional study was conducted using a structured data abstraction format on patients who were attending at the surgical ward of Borumeda hospital from April 1, 2017, to March 31, 2019. The data were collected during July 15-30, 2019. A systematic random sampling technique was employed to select 227 surgical cases. Multivariate logistic regression was computed using the statistical package for social sciences version 23. Results: The incidence of surgical site infections was 46.7%. Prophylaxis was administered to 188 (82.8%) surgical cases. Prophylaxis was recommended for 151 (66.5%). Out of these, only 143 (94.7%) received prophylaxis. One hundred seventy-four (78.4%) of the procedures had appropriate indication. The compliance of surgical antimicrobial prophylaxis use was 13.7%. The predictors of surgical site infections were receiving prophylaxis more than 24 h after surgery (AOR=3.53, 95%