Fracture tibia is common among young population. Present study was aimed to study efficacy of closed intramedullary interlocking nail in achieving anatomical reduction, stable fixation and early return to function among patients with diaphyseal fractures of tibia. Material and Methods: Present study was single-center, prospective, observational study, conducted in patients of age > 18 years, either gender, having closed fracture of the diaphysis of the tibia, posted for the dynamic interlocking nailing. Results: In present study, 120 patients of fractures leg bones were studied, 88 patients were male and majority of the cases were < 45 years of age (70 %). Road traffic accidents were found to amount for most of the injuries (73%) as compared to other modes. Most of the fractures in the study were non comminuted (51 %) and with mild comminutions (31 %). About 100% of the fractures of upper third united by >16 weeks while about 80% of the fractures of middle third united by 16 weeks and about 90% by 20 weeks (average 17 weeks). While about 60% of the distal third fractures united within 16 weeks and 100% by 18 weeks (average 16.5 weeks). Early complications observed were superficial wound infection of the proximal incision site (nine patients), deep infection (one patient), stiff knee joint (two patients), implant failure (two patients), compartment syndrome (one patient), neuro vascular injury/ neuropraxia (one patient) and thromboembolism/ fat embolism (one patient). All patients recovered with conservative treatment. Conclusion: Closed intramedullary interlocking nail for management of diaphyseal fractures of tibia, had achieved good anatomical reduction, stable fixation and early return to function as noted by functional assessment.