Objective: This study aims to assess effect of preoperative vaginal cleansing using chlorhexidine antiseptic on post cesarean section infectious morbidity. Methods: A randomized controlled trial was conducted on a random sample of 178 singleton term pregnant woman assigned for elective cesarean section. A simple random sample was recruited from the operating room of Obstetrics and Gynecology department, Zagazig University Hospitals-Egypt. Participants were randomly assigned either to conventional care group or study group. The conventional care group was exposed to the usual abdominal scrub with Povidone-iodine solution; while the study group subjected to vaginal cleansing using chlorhexidine antiseptic solution in addition to conventional preoperative care. Data were collected using an assessment sheet for demographic and clinical data and checklist for study outcomes. Results: Post intervention, assessment of the incisional wound revealed lower overall post cesarean section infectious morbidity rate among study group compared to those received conventional care (9.0% vs. 20.2% respectively; χ 2 = 4.50, p = .034). Endometritis rate was significantly lower among the study group subjects equated to those of the conventional care group (2.2% vs. 10.1% respectively; χ 2 = 4.75, p = .029), meanwhile febrile morbidity and surgical site infection rates showed non-significant reduction in favor to the study group subjects (p = .469 and .700 respectively). Conclusions: Preoperative vaginal cleansing using chlorhexidine was an effective practice for reducing post cesarean infection; where overall post cesarean infectious morbidity rate was lower among postpartum mothers subjected to vaginal cleansing compared to those exposed to conventional care alone; supporting the study hypothesis.