Introduction: This study assesses the outcome of interlocking tibia nail in comminuted fractures of tibial diaphysis. Objectives: To study the functional outcomes of interlocking tibia nail in comminuted tibial diaphyseal fractures, with respect to time to bony union, mobility achieved, complications of the procedure and secondary procedures. Material and Methods: The present prospective study included 25 patients of comminuted fracture shaft of tibia admitted to the Department of Orthopaedics at MMIMSR, Mullana and at Civil Hospital, Rajpura who were managed with interlocking tibia nail. Results: All 25 cases united with interlocking nailing. 1 case needed additional exchange nailing and bone grafting. 3 cases had a malunion but had an acceptable functional outcome. Conclusions: Due to the simple surgical technique, good healing rate and minimum complications, it is recommended that interlocking tibia nail should be used in comminuted fractures of tibial diaphysis.