Background: The purpose of this study is to examine the incidence, risk factors, and morbidity of postoperative urinary tract infections (UTI) in pediatric surgical patients. Methods: All patients in the 2012-2016 American College of Surgeons National Surgical Quality Improvement Program Pediatric database were included. Demographics, comorbidities, and 30-day outcomes were assessed. Multivariable logistic regression was used to estimate the independent effects of patient and procedure characteristics on the risk for UTI and to estimate the effects of UTI on the risk for readmission and reoperation. Results: Of 369,176 patients, 1964 (0.5%) developed a postoperative UTI. Those undergoing urological and neurosurgical procedures were at greatest risk. Diabetes, ventilator dependence, and dependence on nutritional support each increased the odds of developing a UTI by more than 60% (P < 0.01). On multivariable analysis, UM was an independent risk factor for unplanned readmission (OR, 4.93; 95% CI,439-5.54: P< 0.001) and reoperation (OR, 121; 95% CI, 1.01-1.45; P - 0.041). Conclusion: Urinary tract infection is an uncommon but not inconsequential complication following surgery in the pediatric population and is associated with increased risk of readmission and reoperation. The identification of risk factors for postoperative UTI provides the opportunity for targeted surveillance and patient-specific interventions to prevent UTIs in children at greatest risk. (C) 2019 Elsevier Inc. All rights reserved.