A retrospective cohort study of 668 staged bilateral TKA patients was conducted to determine first-side versus second-side subjective and objective outcomes. Improvement in patient perceived function, measured by one-year Oxford Score (OKS) was defined by a minimal clinically important difference of >5 points in OKS. Results indicate that patients who had a minimal clinically important improvement (MCII) on the first-side have a significantly greater chance of maintaining or improving benefit with second-side TKA (OR 3.2; 95% CI 1.63–6.22; P = 0.000). Of those with no clinical improvement (NCI), 71.4% achieved MCII on the second-side, while 28.6% remained NCI (P = 0.000). Patients who do not initially benefit from first-side TKA should not be denied second-side staged-TKA as they still have a significant chance of achieving an MCII.