Objective: To assess the quality of life of knee osteoarthritis patients using the SF-36 questionnaire. Methods: Cross-sectional study with 93 knee osteoarthritis patients. The sample was categorized according to Ahlbäck score. All individuals were interviewed with the SF-36 questionnaire. Results: The main finding of the study is related to the association of education level with the functional capacity, functional limitation and pain. Patients with higher education level had better functional capacity when they were compared to patients with basic level of education. Conclusion: Individuals with osteoarthritis have a low perception of their quality of life in functional capacity, functional limitation and pain. There is a strong association between low level of education and low perception of quality of life.