Background: Tibial shaft fracture is an incapacitating pediatric injury. The treatment has traditionally been age-related, influenced by the type of injury, associated injuries and the location and type of the fracture. To a great extent, treatment options vary according to the surgeon's preference. Objective: The aim of the present study was to evaluate the results of treatment of displaced diaphyseal fractures of the tibia in children aged between5 and 15 years by closed reduction and percutaneous flexible intramedullary nailing. Patients and methods: A total of 18 patients were included in the study; they were admitted to the hospital suffering from tibial shaft fractures. On admission all patients were assessed by history taking, clinical examination and radiological evaluation. Results: The mean age was 10.22 (SD 1.99) years. Only 5 (27.8%) patients were girls, while 13 (72.2%) patients were boys. The mechanism of trauma in the patients was road traffic accidents in 15 (83.3%) patients and falling from height in 3 (16.7%) patients. Radiographic angulation occurred in 1 patient had varus malalignment (more than 5 and less than 10°). Limb- length inequality is less than 1 cm in all cases. The final results obtained were excellent in 15 (83.3%) patients and satisfactory in 3 (16.7%) patients. There was no statistically significant difference found between two reduction methods (opened and closed) regarding malalignment, complications and score flynn. Conclusion: Flexible intramedullary nailing is a relatively simple and effective way to stabilize open and closed fractures of diaphyseal tibial fractures in the six to twelve years age group with few complications, allowing early mobilization and excellent functional outcome. The procedure has low morbidity and good results with short hospitalization.