Thirty-two patients with acute AO 42-C3 tibial shaft fractures were randomized to receive platelet-rich plasma (PRP) injected at the fracture site after Intramedullary (IM) nailing (n=16) or a normal saline injection (n=16). The primary outcome was cortex-to-callus ratio on serial radiographs. Secondary outcomes included time to union and patient-reported measures (SF-36, EQ-5D-3L, VAS pain). Outcomes were assessed monthly to 6 months. Overall, the results of the study revealed higher cortex-to-callus ratios in the PRP arm at months 3 and 4 and a shorter mean time to union. SF-36 scores were higher with PRP, while VAS and EQ-5D did not differ. These findings suggest PRP hastens mid-stage callus formation and accelerates union after IM nailing of highly comminuted tibial shaft fractures.