Femoral shaft fractures are common fractures in paediatric age group. In children, fractures of the femoral shaft have been traditionally treated mostly by conservatively immobilization in a Spica cast, either immediately or after a period of traction. But this safe form of treatment has major drawbacks. The management of paediatric femoral shaft fractures gradually has evolved towards a more operative approach in the past decade. Elastic stable intramedullary nailing (ESIN) or Titanium elastic nailing system (TENS) is a recent technique which allows stable reduction, maintenance of reduction and early mobilization. . Aim of study is to assess the functional outcome of fracture shaft of femur in pediatric age group treated with titanium elastic nailing system. It is a prospective study which was conducted in the all children between 5-14 years of age with diaphyseal fractures of femur. Outcome of  fracture  shaft  of  femur  in  pediatric  age  group  treated  with titanium elastic nailing system was studied studied by observing following, Type of reduction among children with diaphyseal fractures of femur, .Duration for union after surgery , Range of motion after surger, weeks of  Weight Bearing started , Limb length discrepancy, Malalignment . From present study we conclude that femur diaphyseal fracture in children between 5-14 years of age can be effectively managed with titanium elastic nails. TENS offers a biological, minimally invasive method of treatment for fracture shaft of femur in children with advantages of sufficient axial stability, early mobilization and more rapid return to function. this technique yields higher rate of excellent functional outcome. Keywords: Femur, Diaphyseal Fracture,  Children, TENS