The purpose of this study was to evaluate and assess the sporting and physical activities of patients who had undergone an Oxford medial unicompartmental knee arthroplasty (UKA). Seventy-six patients who underwent a UKA between 2000 and 2003 were reviewed. Demographic data such as age, sex and comorbidities were recorded. University of California Los Angeles (UCLA) activity level ratings and Oxford knee scores were determined for each patient. The sporting and physical activities of all patients' pre- and post-operatively were recorded. The mean age of patients was 64 years (range 49-81) at surgery and 66 years (range 53-82) at review. The mean follow up time was 18 months (range 4-46). Following surgery there was a significant improvement in UCLA activity level scores from 4.2 to 6.5 (Wilcoxon Matched-pairs Signed-rank Test, p<0.01). Forty-two patients (64%) regularly participated in sport before they became symptomatic with significant knee pain, and thirty-nine patients (59%) regularly participated in sports after surgery. In total 93% of patients successfully returned to their regular sporting and physical activities following surgery. The published long-term survivorship of the Oxford UKA has given surgeons increasing confidence to use the prosthesis on a younger generation of patients. Our study has demonstrated that this population of patients is extremely active. A more detailed study is required to evaluate the long-term effects of sporting activity on the Oxford UKA.