Background: Advantages of the elastic intramedullary nailing (EIN) in treating diaphyseal fractures of the femur include the reduction of nearly all complications. Objective: The aim of the current work was to evaluate the results of treatment of diaphyseal fractures of the femur in children using intramedullary elastic nail.   Patients and Methods: This prospective clinical trial study included a total of 18 children with femoral diaphyseal fracture treated with elastic intramedullary nails. They were admitted at the Department of Orthopedic Surgery, Zagazig University Hospitals, Egypt and Abusalim Trauma Hospital, Libya. This study was conducted between November 2021 to May 2022.  All patients were followed up for six months. Results: According to Flynn's score, the outcomes of the operation were excellent in 14 cases, satisfactory in 3 cases, and poor in 1 case. The 18 cases were united with radiological assessment. Only 1 case had superficial skin infection and just one case had mild pain. Conclusion: It could be concluded that if used appropriately, elastic stable intramedullary nailing (ESIN) is a successful treatment for fracture femur in children with very few consequences.