Elastic stable intramedullary nailing (ESIN) is the current preferred method for treating diaphyseal femur fractures in children. Introduction of the submuscular locked plate (SMP) fixation construct has opened the debate on treatment options for pediatric diaphyseal femur fractures in the older children and adolescents. A randomized controlled trial (RCT) protocol was designed to compare ESIN and SMP for diaphyseal femur fractures in children. An open-labelled RCT comparing SMP with ESIN was conducted from January 2013 to June 2016, for children aged 6-15 years with closed, acute femoral diaphyseal fractures. Randomization was done through computergenerated randomization sequence and opaque-sealed envelopes. Rate of adverse surgical events including unplanned re-operations was assessed as the primary outcome and secondary analysis was done for time to union, degree of malunion, limb length discrepancy, functional outcome at 2 years, surgical duration and blood loss, radiation exposure, hospital stay, cost incurred and secondary implant removal procedure. Forty children were randomized with allocation concealment. There were three adverse events in the SMP arm and five in the ESIN arm. Fifteen children with SMP underwent routine implant removal compared to only three children with ESIN (P < 0.001). Both ESIN and SMP are equally safe, viable and effective options for treating pediatric diaphyseal femoral fractures. However, the additional cost of secondary surgery for implant removal in the SMP group proved to be a deterrent factor, which led to ESIN being the preferred option in our resource-limited setting. J