Objective To retrospectively analyze the short-term therapeutic effect of proximal fibular osteotomy in the treatment of medial compartment osteoarthritis of the knee. Methods A total of 42 patients with medial compartment osteoarthritis of the knee who underwent proximal fibular osteotomy in the Second Department of Orthopedics， Jiangmen Wuyi Hospital of Traditional Chinese Medicine from December 2014 to March 2017 were enrolled in this study. There were 8 males and 34 females， aged 65 ~ 81 years and weighing 48 ~ 56 kg. The therapeutic effects were evaluated before and after operation， including VAS score， maximum flexion angle， Knee Society Score （KSS） knee score， KSS function score， and Western Ontario and McMaster Universities Osteoarthritis Index （WOMAC） score. Results All the 42 patients were followed up for one year. The VAS score significantly decreased from 5.82 ± 1.54 before operation to 2.43 ± 0.94 at 12 months after operation; the maximum flexion angle significantly increased from 90.12 ± 9.18 before operation to 100.03 ± 8.91 at 12 months after operation; the KSS knee score significantly increased from 52.32 ± 6.46 before operation to 87.09 ± 2.72 at 12 months after operation; the KSS function score significantly increased from 45.62 ± 3.31 before operation to 71.12 ± 5.73 at 12 months after operation; the score of WOMAC significantly decreased from 120.42 ± 6.31 before operation to 46.93 ± 5.46 at 12 months after operation （all P < 0.001）. After operation， the incision of all patients healed by first intention; the pain of the knee joint was obviously relieved and even disappeared， but 1 case complained of numbness of the lateral lower leg and 2 patients complained of soreness and weakness of the knee joint. The symptoms disappeared after symptomatic treatment. Conclusion Proximal fibular osteotomy is an effective method for the treatment of medial compartment osteoarthritis of the knee joint， with advantages of simple operation， small trauma， low cost， and effective relief of knee joint pain.