BACKGROUND: Surgical site infection (SSI) after cesarean section (CS) increases maternal morbidity, hospital stay and medical cost. However, in Ethiopia, limited evidence exists regarding the magnitude and risk factors of post-CS wound infection. The purpose of this study was to determine the prevalence of – and factors associated with the problem among mothers who gave birth in Hawassa University Teaching and Referral Hospital, Southern Ethiopia.METHODS: Hospital based cross-sectional study was conducted based on the medical records of 592 women who underwent CS from June 2012 to May 2013. Data on the occurrence and factors associated with SSIs were extracted. Factors associated with SSI were identified using multivariate logistic regression analysis. The output of the analysis is presented using adjusted odds ratio (OR) with the corresponding 95% confidence interval (CI).RESULTS: The prevalence of SSI was 11.0% (95% CI: 8.6-13.8%). Mothers with prolonged labor (6.78, 95% CI: 2.54-18.00) and prolonged rupture of membrane (5.83, 95% CI:  2.14-15.89) had significantly increased odds of SSI. Compared to mothers who had no digital vaginal examination, those who had 1-4 and 5 or more examinations were at higher risk with OR of 2.91 (95% CI: 1.21-6.99) and 8.59 (95% CI: 1.74-42.23), respectively. Prolonged duration of surgery (12.32, 95% CI: 5.46-27.77), wound contamination class III (9.61, 95% CI: 1.84-50.06) and postoperative anemia (2.62, 95% CI: 1.21-5.69) were also significant predictors. CS conducted by junior practitioners is likely to be followed by infection.CONCLUSION: Post-CS SSI is relatively common in the hospital. Thus, it should be averted by implementing infection prevention techniques. KEYWORDS: Surgical wound infection, Cesarean section, Southern Ethiopia