Abstract Background: Diaphyseal femur fractures are commonly encountered in association with other high-energy injuries. Fixation of femur fractures in children & adolescents by flexible intramedullary nailing is becoming widely accepted because of the lower chance of iatrogenic infection. The objective of the study was to observe functional outcome, healing time and the complications following the use of flexible nail for femoral shaft fractures. Methodology: Children and adolescents between the age group of 5-16 years with Femoral shaft fractures were admitted to Hospitals attached to J.J.M Medical College, Davangere. All patients were operated by closed reduction and internal fixation with flexible nailing. Patients were followed up after surgery. A minimum of 20 cases were studied. Results: The study comprised 16 male patients and 4 female patients aged from 5 to 16 years with mean of 8.5 years. The commonest duration from date of injury so far of surgery was 2 to 4 days. From 3 months to 1 year range was there to follow up. Conclusion: Rapid healing and fracture union by preservation of fracture hematoma and limited soft tissue exposure was observed in flexible intramedullary nail fixation. We conclude that flexible intramedullary nailing is a superb technique for the treatment of diaphyseal fractures of the femur in| children and adolescents aged 5 to 16 years. Keywords: Femoral shaft; Intra medullary; Diaphyseal; Flexible nails