Aims: To compare objective and subjective methods of assessment of outcome following total knee replacement. Methods: A retrospective review of 560 consecutive total knee replacements, performed under the care of a single surgeon, between January 1990 and January 2000, on 456 patients, was carried out. Minimum follow-up was two years. The patients were assessed using two postal questionnaires, a clinical interview and examination and a radiological investigation. The results from each assessment were entered into a database and evaluated. Results: The results from the postal and direct questionnaires were comparable. These results correlated well with clinical and radiographic evaluation. A simply worded questionnaire was found to be more user- friendly than a complex questionnaire. Questions about specific daily activities were less user-friendly than questions about general function. Conclusions: A simple postal questionnaire provides an accurate reflection of outcome after total knee arthroplasty. This has significant implications with regard to cost and clinical time when planning follow-up after knee replacement.