Abstract:[Objective] To compare the clinical outcomes of Oxford unicompartmental knee arthroplasty (UKA) between patients older and younger than 60 years, and to discuss the ideal indications of Oxford UKA. [Methods] A total of 112 patients who received primary UKA for knee osteoarthritis (KOA) from March 2014 to December 2017 were retrospectively reviewed. The patients were divided into two groups according to age at surgical procedure, the <60 group and the ≥60 group, with 56 cases in each group. The data regarding to perioperative pe- riod, follow-up and radiographs were compared between the two groups. [Results] All patients in both groups had UKA performed success- fully without serious complications. There were no significant differences in operation time, total length of surgical incision, intraoperative blood loss, time to walk down the ground, grade of incision healing and hospital stay between the two groups (P>0.05). All patients were fol- lowed up for (69.2±5.3) months on an average, and there was no a significant difference in the time to resume full weight-bearing activities between the two groups (P>0.05). As time went by, the VAS score was significantly decreased (P<0.05), while HSS score, KSS clinical and functional scores and knee extension-flexion range of motion (ROM) significantly increased in both groups (P<0.05). There was no signifi- cant difference in the above items between the two groups before surgery and 6 months after surgery (P>0.05). The <60 group got significant- ly higher KSS clinical score than the ≥60 group at the latest follow-up (P<0.05), despite that there were no significant differences in knee VAS score, HSS score, KSS functional score and knee ROM between the two groups (P>0.05). Regarding imaging, femorotibial angle (FTA), mLDFA angle and mMPTA angle significantly improved postoperatively compared with those preoperatively in both groups (P<0.05), which proved not statistically significantly different at any corresponding time points between the two groups (P>0.05). [Conclusion] Patients re- ceiving Oxford UKA in age under 60 years show better clinical outcomes in at least 5 years of follow-up, although there was no considerably difference in functional outcomes with those aged ≥60 years.