Abstract: Objective To compare the clinical effects of minimally invasive percutaneous plate osteosynthesis (MIPO) and minimally invasive intramedullary nailing osteosynthesis (MINO) in the treatment of humeral shaft fractures. Methods The clinical data of 53 patients with humeral shaft fractures treated with MIPO and MINO were retrospectively analyzed. The patients were divided into MIPO group of 25 patients and MINO group of 28 patients according to differed surgical approaches. The operation time, blood loss, length of hospital stay, fracture healing time, University of California at Los Angeles (UCLA) shoulder function score at 1 year postoperatively, and Mayo elbow performance score at 1 year postoperatively were compared between the two groups. Results All 53 patients successfully completed the surgery, and no postoperative complications such as surgical site infection, radial nerve injury, fracture nonunion, implant breakage, or loosening occurred. There were no statistically significant differences between the two groups in terms of operation time, blood loss, length of hospital stay, fracture healing time, and Mayo elbow performance score at 1 year postoperatively (P>0.05). The UCLA shoulder function score at 1 year postoperatively was better in the MIPO group than in the MINO group (P<0.05). One patient in the MIPO group experienced wound fat liquefaction, and one patient in the MINO group experienced radial nerve palsy. Conclusion Both MIPO and MINO can achieve satisfactory results in the treatment of humeral shaft fractures, and both minimally invasive techniques are worthy of clinical promotion. However, MIPO has lesser impact on shoulder function.