Introduction: Reduction mammoplasty is becoming more commonly performed in the pediatric population yet the risk factors for complications have not been well-studied. The purpose of this study was to assess the relationship between preoperative patient characteristics and postoperative complications in a large population of pediatric patients undergoing reduction mammoplasty. Methods: Pediatric patients undergoing reduction mammoplasty were identified within the 2012 to 2019 National Surgical Quality Improvement Program database for cross-sectional study. The predictor variables were age, body mass index (BMI), diabetes, chronic steroid use, time under anesthesia, and operative time, and the primary outcome was a 30-day postoperative surgical site-related complication. Multivariate logistic regression was performed to identify a relationship between predictor variable and primary outcome. Results: A total of 1216 pediatric patients were identified with a mean age of 16.6 years and mean BMI of 30.8 kg/m 2 . The incidence of overall postoperative complications was 4.6%. Superficial surgical site infection (SSI) was the most common complication (29/1216; 2.4%). BMI was significantly associated with superficial SSI (odds ratio: 1.03, 95% confidence interval: 1.00-1.05, P = .02) . Sixteen patients (1.32%) underwent a second operation, most commonly to address hematoma/seroma (7/16; 43.8%). Conclusion: In a large series of patients, pediatric reduction mammoplasty is a safe procedure with a low complication rate. BMI was significantly associated with the incidence of superficial SSIs with the most common cause for reoperation being a hematoma/seroma. This study can help guide the discussion between physicians and patients regarding potential risks associated with pediatric reduction mammoplasty., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© 2022 The Author(s).)