OBJECTIVES: This study aimed to explore risk factors for failure of forearm fracture closed reduction in the pediatric emergency department (ED) and to suggest indications for initial surgery. METHODS: This retrospective cohort study included all patients aged 0 to 18 years who presented to our pediatric ED with an extraarticular forearm fracture treated with closed reduction between May 2017 and April 2021. We explored risk factors for procedural failure, defined as a need for surgical intervention within 6 weeks of the closed reduction attempt. RESULTS: Of 375 patients (median age 8.1 years, 294 [78.2%] boys), 44 (11.7%) patients sustained a reduction failure, of whom 42 (95.5%) had both radius and ulna fractures. Of the 259 patients with fractures of both bones, the following parameters were independent predictors for reduction failure: refracture (adjusted odds ratio [aOR] 17.6, P < 0.001), open fracture (aOR 10.1, P = 0.007), midshaft fracture (aOR 2.6, P = 0.004), radial translation rate 37% and higher in either plane (aOR 5.1, P = 0.004), and age of 10 years and older (aOR 2.9, P = 0.01). CONCLUSIONS: Most pediatric forearm fractures can be successfully managed by closed reduction in the ED. Two-bone fractures had the strongest association with reduction failure. Refracture, open fracture, midshaft location, initial radius bone translation of 37% and higher (and not initial angulation), and patient age of 10 years and older are independent risk factors for reduction failure in two-bone fractures. We propose a risk score for reduction failure that can serve as a decision-making tool.