Abstract Diaphyseal tibial fracture is the most common fractured long bone because of it is subcutaneous position anteromedially and thinner diaphysis distally. Tibial diaphysis has poor blood supply and poor soft tissue envelope around it so it is more susceptible to infection, delay union, and non-union. For these reasons many modalities including cast and brace, external fixation, plate and screws, and locking intramedullary nail were used for treating diaphyseal tibial fracture. The aim of this study is to compare the outcome of locking intramedullary nail(LIMN) fixation versus plate and screws fixation in treating diaphyseal tibial fracture in term of operation time, early weight bearing, time to union, and complications. The study was carried out in Sulaimaniyah Teaching Hospital, Department of Orthopedics prospectively from May 2010 to July 2014 on 74 patients, 40 of them underwent surgical fixation by locking intramedullary nail (26 close method and 14 by open method), and 34 of them underwent open reduction and internal fixation by plate and screws. The outcome was assessed by clinical and radiological evaluation. The results show that young male are more affected by trauma, and the main mechanism of injury was Road Traffic Accident. Operation time was shorter among plate and screws group with a mean of 51.4±4.9 minutes, than locking intramedullary nail group with a mean of 88.5±12.5 minutes. Weight bearing(WB) time achieved earlier in the locking intramedullary nail group with a mean of 2.6±0.8 weeks than the plate and screws group with a mean of 4.2±1.4 weeks. There were no significant difference between the two groups regarding time to full weight bearing(FWB), time to union, and complications. In conclusion, Locking intramedullary nail and plate fixation are ideal option for treatment of diaphyseal tibial fractures since there were no significant differences between them in time of union and the post-operative complications.