Open fractures have been associated with a higher risk of infection if antibiotics are not administered within 1h of presentation in adult trauma patients. Time to antibiotic administration for open fractures is frequently used as a quality metric for trauma centers, but there have been no large studies evaluating this topic for pediatric patients. The 2019 Trauma Quality Improvement Program dataset was queried for patients ≤ 16 years old with isolated open femur or tibia fractures undergoing operative intervention after blunt trauma. Patients transferred from another hospital were excluded. Pediatric patients receiving early antibiotics (EA) within 1h were compared to patients receiving delayed antibiotics (DA) greater than or equal to 1h from arrival. Multivariate logistic regression was used to evaluate risk of surgical site infection (SSI). There were 150 patients with open lower extremity fractures: 98 (64.9%) EA vs 52 (34.4%) DA. There was no difference in the rate of SSI between the 2 groups (EA: 1.0% vs DA: 1.9%, P = 0.65). There remained similar associated risk of infection after adjusting for lower extremity abbreviated injury scale >3, blood transfusion requirement, and vital signs on arrival (OR 0.62, 95% CI 0.04-10.24, P = 0.74). Most pediatric trauma patients with open lower extremity fracture received antibiotics within 1h of presentation. However, SSI was rare and the risk of SSI was not associated with antibiotic administration within 1h. Therefore, timing of antibiotic administration for pediatric open lower extremity fractures should be re-evaluated as a quality metric.Level of Evidence: Level III.