Background: Prior studies have compared unicompartmental knee arthroplasty (UKA) with high tibial osteotomy (HTO) suggesting that both procedures had good clinical outcomes. However, which treatment is more beneficial for unicompartmental knee osteoarthritis is still a controversy. The purpose of our study is to obtain postoperative outcomes of revision rate, complications, function results, range of motion (ROM), and pain between the 2 procedures. Methods: Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed and study protocol was published online at PROSPERO under registration number CRD42016049316. We searched the databases MEDLINE, EMBASE, Cochrane Library, and Web of Science up to May 2017. Articles that directly compared postoperative outcomes of UKA to HTO were included. Results: A total of 10 comparative studies were included in our meta-analysis. UKA patients showed less revision rate, less complications, and less postoperative pain than HTO patients; however, HTO patients obtained more ROM. No significant difference was observed between the group accruing to the knee function scores and excellent/good surgical results. Conclusion: UKA offers a safe and efficient alternative to osteoarthritis reduced postoperative pain, less postoperative complication, and revision. The 2 surgical techniques showed satisfactory function results for the patients; however, the HTO group achieved superior ROM compared to the UKA group. HTO may be suitable for patients with high activity requirements. Treatment options should be carefully considered for each patient in accordance with their age, body mass index, grade of osteoarthritis, and patients' activity levels. (C) 2017 Elsevier Inc. All rights reserved.