The importance of this biological and minimally invasive fracture treatment is to achieve anatomical reduction and stabilization, which is not expected by conservative methods. The biological principle of the elastic nail is based on symmetrical bracing action of two elastic nails inserted into the metaphysis across the fracture site, each of which bears against the inner bone surface at 3 points. Diaphyseal fractures of the femur and tibia accounts for 10- 15% of all paediatric fractures. This novel technique of elastic stable intramedullary nailing (ESIN) has dramatically changed the treatment of pediatric fractures. The objective of current study was evaluate the outcome, safety and efficacy of diaphysis fracture of femur and tibia in children - treated by Titanium Elastic Nailing System (TENS). This observational, interventional study was conducted in 30 patients in the age group of 6-12 years old children, with fractures of long bones with Inclusion criteria: 6-12 years of age, Diaphyseal fractures, closed fractures, Ipsilateral fractures, Fractures with head injury and exclusion criteria: of Metaphyseal fractures, Compound fractures, Pathological fractures, Age group below 6 years and above 12 years. TENS technique was used to stabilize these fractures. Patients were followed-up clinically as well as radio-logically at 3,6,12 and 24 weeks and evaluated by Flynn criteria. The current study had shown excellent results in 17 fractures (77.3%), good in 3 fractures (13.6%) and 2 cases has shown (9%) poor in femur fractures. Tibia results were excellent in 5 fractures (62.5%) and good in 3 fractures (37.5%) with no poor results. Conclusion: This study concludes that Titanium Elastic Nail System (TENS) technique is an ideal treatment method for treatment of pediatric Diaphyseal fractures of lower limb bones.