Background: Fractures of both the ulna and radius, known as both-bone forearm fractures are common among the pediatric population. However, ulnar nerve palsy is a rare complication. Nerve damage can be due to multiple factors. Identification of the type of nerve damage is vital for proper management of this complication. Here, we present a case of ulnar nerve palsy complicating a closed both-bone forearm fracture in a pediatric patient. Furthermore, we explored how to best manage such cases and decrease permanent nerve damage through a literature review. Case presentation: A 10-year-old boy presented to the emergency department (ED) 1 day after sustaining a closed right forearm fracture due to a fall. Examination at our ED revealed intact vascularity and nerve function. Reduction and casting were performed. On follow-up 7 days later, signs of ulnar nerve palsy in the form of decreased sensation in the little finger and weak abduction and adduction of the fingers were present. The patient was admitted and underwent closed reduction with percutaneous elastic stable intramedullary nailing. We found 14 case reports in the literature with similar case presentations. These fractures are commonly managed conservatively by closed reduction, casting, and rehabilitation. However, in both-bone forearm fractures, management began with observation, with surgical exploration being reserved for non-improving patients. Conclusion: The uncommon occurrence of ulnar nerve palsy after closed forearm fractures in children should alert physicians to maintain a high index of suspicion and to thoroughly evaluate nerve function in children both before and after reduction of forearm fractures. Surgical exploration is recommended in cases of delayed recovery of nerve function.