Background: osteoarthritis is a degenerative disease affecting both genders and is more prevalent in females. The incidence of osteoarthritis in Saudi Arabia is up to 60%. Management is initially conservative with medications and lifestyle changes. Total knee arthroplasty (TKA) is the surgical option for patients who complain of severe pain and functional disabilities. TKA is correlated with improving quality of life, but despite this evidence, some patients complain of residual symptoms postoperatively which don't meet their pre-operative expectations. Aim of the work: this study aimed to determine health related quality of life of patients after total knee arthroplasty and to assess the psychological factors affecting the patients after the procedure Methodology: this retrospective cross-sectional study analyzed all the files of patients who underwent unilateral or bilateral TKA in KAUH from 2010-2017. A total of 78 patients were interviewed by phone using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and short form quality of life (SF-36)questionnaires. Result: a total of 78 patients (60 Females and 18 males) were participated in this study. The mean age was 65.7 years old.In general, 41.6% of the patients were satisfied with their usual daily activity, where on the other hand 5.2% of patients reported poor satisfaction and were much worse than before.59.7% of the patients reported great improvement in comparison with the previous year and 22.1% of the patients reported a somewhat better improvement.53.2% reported no limitation in their social life regarding physical activity and emotional problems, while 9.1% had physical and emotional problems interfering with their life. Conclusion: TKA is a very successful and cost effective therapeutic option for treating knee osteoarthritis. Improvement in the quality of life and physical activity of patients supports other conducted previous studies.