INTRODUCTION: Tibial fractures are known to be associated with elevated compartment pressures, which may potentially result in a compartment syndrome. The Tibial Less Invasive Stabilization System (LISS PLT) is an internal fixator device that is designed for fixation of proximal tibia fractures. The technique includes submuscular placement of the implant along the lateral border of the tibia. Such placement of the Tibia LISS into the anterior leg compartment could increase compartment pressures, and therefore increase the risk of compartment syndrome. The objective of this prospective study is to determine whether submuscular placement of a tibia LISS fixator increases compartment pressures and what is the incidence of compartment syndrome. MATERIALS AND METHODS: Twenty-eight consecutive proximal tibia fractures were fixed using the Tibia LISS (LISS PLT). Compartment pressures in all four leg compartments were measured pre- and postoperatively. Diastolic pressures were recorded and perfusion pressures calculated. RESULTS: There were no statistically significant differences between pre- and postoperative compartment pressures. One patient out of twenty-eight developed an impending compartment syndrome after placement of the LISS implant. CONCLUSIONS: Submuscular fixation of the tibia with the Less Invasive Stabilization System does not cause a significant rise in leg compartment pressures, nor is it associated with an increased incidence of compartment syndrome.