Background: Surgical site infection is the main cause of morbidity and mortality in post-cesarean section patients. The objective of this study was to determine the preoperative factors associated with the surgical site infection in patients undergoing cesarean emergency section in the Goyeneche Hospital of Arequipa. Methods: We conducted a cases-control study on women who presented with surgical site infection after cesarean section in a hospital in Arequipa, Peru. We evaluated associated factors to surgical site infection after cesarean section (sociodemographics and clinical variables). For the inferential analysis, we estimated logistic regression using odds ratio. Results: Out of a total of 4346 cesarean sections, only 2.4% developed surgical site infection. The associated factors to surgical site infection were mild anemia (OR: 2.80), moderate anemia (OR: 2.71), number of vaginal examinations higher than five (OR:2.71) and onset of labor (OR: 1.95). Conclusion: Patients with risk factors such as anemia, onset of labor and five or more vaginal examinations should be evaluated after surgery to prevent surgical site infection.