Abstract:[Objective] To introduce the surgical technique and preliminary clinical results of intramedullary nailing via infrapatellar approach in lateral position for fixation of tibial shaft fractures. [Methods] From June 2015 to September 2019, a total of 103 patients un- derwent closed reduction and internal fixation for tibial shaft fracture. The patient was placed in lateral decubitus, and the affected knee was positioned in 90 degrees of flexion. Under axial traction, the fractures were closely reduced manually. An infrapatellar incision was made, and then the patellar tendon was split longitudinally to expose the proximal tibia. As a guide pin was inserted into the medullary cavi- ty from the proximal tibia, reaming was conducted and a main nail in proper size was inserted following the guide pin. After satisfactory frac- tures reduction and proper position verified fluoroscopically, the guide pin was removed, and interlocking screws were placed distally and proximally. [Results] All patients were successfully operated on without serious complications such as vascular and nerve injury, whereas with intraoperative fluoroscopy of (10.80±2.43) times, successful guide pin placement in the first time in 84 cases (81.55%) , operation time of (72.98±14.21) min. The patients got clinical fracture healing in (14.03±5.98) weeks, with LEFS score of (77.19±2.39) 12 months after op- eration. Of them, 17 case had anterior knee pain and 5 had malunion, whereas none of deep infection and fracture nonunion was noted at the latest follow up. [Conclusion] Intramedullary nailing via infrapatellar approach in lateral position for tibial shaft fractures is a comfort- able position with advantages of convenience to intraoperative fluoroscopy, shortening operation time and reducing number of assistants.