Objective: The aim of this study was to validate the well-recognized outcome measure instruments (Medical Outcome Study Short Form-SF-36, Western Ontario and McMaster University Osteoarthritis Index-WOMAC, McMaster Toronto Arthritis Patient Preference Disability Questionnaire-MACTAR) for patients who had undergone total knee arthroplasty in Iran, with its cultural and ethnic differences and compare them with the reports from other parts of the world. Methods: Sixty patients, 56 women and 4 men, who had undergone total knee arthroplasty by a single surgeon, were recruited for clinical evaluation and for filling out the questionnaires on 3 outcome instrument systems, namely SF-36, WOMAC and MACTAR. Two control groups consisting of 44 cases of similar age from general population with knee discomfort and susceptible to osteoarthritis as well as 26 patients scheduled for knee arthroplasty filled out the same questionnaires. Results: The health status measurement (SF-36), disease-specific outcome measure and patient preference arthritis scores all showed significant improvement in operated cases, in both short and long term follow-up groups. Certain aspects of function like socialization with others, attending religious ceremonies and similar activities, often requiring full knee bending and/or sitting on the carpeted floor, were the main reasons for dissatisfaction with the procedure. Conclusion: The knee arthroplasty increased quality of life, improved function and produced great satisfaction in the majority of cases in our society. This is, however, a viable option for people who could change their lifestyle and household and are able to make the adjustments mentally and financially.