Staged bilateral total knee arthroplasty is performed increasingly frequently but no data has been published comparing the specific outcome for the first knee replacement to that of the second. Pre-operative and post-operative Oxford Knee Scores (/ 48) were reviewed for each knee in a series of 91 patients undergoing staged bilateral total knee arthroplasty over a 5-year period. Pre-operative scores for the first total knee arthroplasty were significantly worse with a mean of 14.9 in comparison to 17.0 for the second knee (P=0.0083). While there was no significant difference between the mean post-operative scores for the first knee (37.4) and the second knee (36.6) (P=0.195), the mean improvement was significantly less for the second knee (22.6 points versus 19.6 points) (P=0.0045). Our results demonstrate that in patients undergoing staged bilateral knee arthroplasty, the second knee replacement is commonly performed at a lower threshold and functional improvement is less than for the first knee. This data will be important to inform the expectations of patients considering proceeding to bilateral knee arthroplasty after previously having undergone a primary total knee replacement