ABSTRACT: OBJECTIVE:To examine the association of a resident-driven quality initiative with cesarean delivery surgical site infections. METHODS:This was a quasi-experimental, preintervention and postintervention study of women undergoing cesarean delivery at 23 weeks of gestation or greater between January 2015 and June 2018 at a single tertiary care center. We implemented a resident-driven, evidence-based surgical bundle, excluding women who underwent emergency cesarean or had chorioamnionitis. The bundle included routine prophylactic antibiotics (both cefazolin and azithromycin), chlorhexidine alcohol skin preparation, use of clippers instead of a razor, vaginal cleansing with povidone iodine, placental removal by umbilical cord traction, subcutaneous tissue closure if wound thickness greater than 2 cm, suture skin closure, dressing removal between 24 and 48 hours, and use of postoperative chlorhexidine soap. Our primary outcome was surgical site infections (superficial incisional, deep incisional, and organ or space surgical site infections) occurring up to 6 weeks postpartum. Outcomes were compared between the preimplementation period (January 2015-August 2016) and postimplementation period (December 2016-June 2018). Coarsened Exact Matching with k-to-k solution was performed using age, race-ethnicity, body mass index, rupture of membranes, and labor. RESULTS:In total, 1,624 underwent cesarean delivery in the preimplementation and 1,523 postimplementation periods, respectively; 1,100 women in the postimplementation period were matched to 1,100 women in the preimplementation period. The rate of surgical site infections in the unmatched cohort was significantly lower in the postimplementation period compared to those in the preimplementation period (2.2% [33/1,523] vs 4.5% [73/1,624]; odds ratio [OR] 0.47 [95% CI 0.31-0.71]; P<.001). This decrease in the rate of surgical site infections remained statistically significant after matching (1.9% [21/1,100] vs 4.1% [45/1,100]; OR 0.46 [0.27-0.77]; P<.001). CONCLUSION:After implementation of a resident-driven quality initiative using a surgical bundle, we observed a significant decrease in cesarean surgical site infections.