Grade III Open fractures of the tibia represent a serious injury. It is recognised that combined management of these cases by experienced orthopaedic and plastic surgeons improves outcomes. Previous studies have not considered the timing of definitive soft tissue cover in relation to the definitive orthopaedic management. We reviewed medical notes of 73 patients with 74 Grade III Open tibia fractures (minimum 1 year follow up), to compare deep infection rates in patients who had a) a single-stage definitive fixation and soft tissue coverage vs. those who had separate operations, and b) those who had definitive treatment completed in < 72 hours vs. > 72 hours. Of subjects that underwent definitive fixation and coverage in a single procedure, 4.2% developed deep infections, compared with 34.6 % deep infection(p<0.001) in those who underwent definitive treatment at separate operations. Of patients who had definitive treatment completed in < 72-hours, 20.0% developed deep infections a compared with 12.2%(p=0.4919) in the >72-hour group. Patients with Gustilo III open tibial fractures have lower rates of deep infection if definitive fixation and coverage are performed in a single-stage procedure. Emphasis should be placed on timely transfer to a specialist centre, aiming for a single-stage combined orthoplastic surgery.