Introduction: More than 100 million populations globally suffer from Osteoarthritis (OA) which is considered the leading cause of disability. The prevalence of OA knee in India is about 6% of total osteoarthritis. Therefore, there is a need for alternative and well-tolerable supplementary treatment which has no drug interaction with conventional drugs for OA. Aim and objectives: To evaluate the effect of traditional sudation therapy (Nadi Swedana) on pain, swelling and stiffness of patients with knee osteoarthritis. Method: The study was conducted after getting approval from Institutional Ethical Committee and was registered to the Clinical Trials Registry of India (CTRI/2018/03/012636 19/03/2018). A total of 20 patients with knee joint osteoarthritis were treated for 6 weeks. Pre-test and the post-test outcome measure was recorded on subjective parameters and statistically analyzed. Results: The applied score for pain, swelling and stiffness decreased significantly lower after the intervention (p<0.05). Conclusions: Traditional sudation therapy by Nadi Swedana was beneficial for patients with knee osteoarthritis.