Flexible intramedullary nailing and external fixation have become the main methods to surgically treat femur fractures in children. This study aimed to search the current literature and evaluate the clinical and radiographic results of surgical treatment by comparing these methods and investigating their associated complications. This systematic review was carried out following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) recommendations. Searches were carried out on the PubMed, Embase, and Web of Science databases. The search for journals in these databases was carried out from January 2023 to August 2023, retrieving 695 studies. This systematic review included 11 articles, which encompassed 718 patients who underwent surgical external fixation and flexible nailing. The most frequently observed complications referred to late or malunion, superficial and deep infections, skin irritation, angular deformity, and length discrepancy between lower limbs. Both methods of stabilization of pediatric femoral fractures can provide good clinical and radiographic results. However, the choice of treatment with flexible nails is certainly more valid and has greater acceptance than external fixation. Level of Evidence III, Systematic Review .