Telephone and postal methods of administration of the Oxford Knee Score (OKS) and the Oxford Hip Score (OHS) were compared on 85 and 61 patients undergoing total knee arthroplasty (TKA) and total hip arthroplasty (THA), respectively. The test for equivalence was significant for both the knee (P < 0.001) and hip participants (P < 0.001) indicating that the modes of administration yielded similar results. The ICCs of the OKS and OHS were 0.79 (95% Confidence Interval (CI) 0.70, 0.86) and 0.87 (0.79, 0.92) respectively. The 95% limits of agreement were wide for both scores (OKS LOA, −8.6, 8.2; OHS LOA, −7.7, 5.3). The two modes of administration of the OKS and OHS produce equivalent survey responses at a group level but the same method of administration should be constant for individual monitoring in a clinical setting.