Background: Knee Osteoarthritis (OA) is a chronic disease, the second leading cause of disability for the elderly after cardiovascular disease. Treatment with traditional medicine is highly effective, has safety in the long run and has few side effects. Beside, herbal steaming is a simple, easy-to-implement treatment method that works quickly and can be widely applied in the community. Objectves: To evaluate treatment effects of electro-acupuncture and San-bi-tang remedy combined with herbal steam in patients of primary knee osteoarthritis. Subjects and Methods: Clinical trial with comparison before and after treatment, from August 2019 to May 2020, on 58 patients diagnosed with primary knee OA according to the standards of the American Society of Rheumatology (ACR), X -ray phase I, II according to Kellgren & Lawrence, Wind Cold Damp clinical forms or Wind Cold Damp together with Liver and kidney damage clinical forms according to traditional medicine. Patients were assessed clinically, subclinical, and VAS scale, Lequesne index, WOMAC index, heel-buttock index, Rank of Motion (ROM) at baseline and after 9 days (D9), 18 days (D18). Results: Mean VAS score decreased to 1.60 ± 1.32 points (compared with 6.26 ± 1.00 points at D0; 3.98 ± 1.36 points at D9), the difference was statistically significant (p < 0.05). Lequesne index decreased significantly at the time D18, D9 compared with the time D0, at the time of D18 Lequesne average point was 5.01 ± 2.10 (p < 0.05). WOMAC index: After 18 days of treatment, there was no patient with severe or moderate dysfunction. Patients distributed at non-dysfunctional levels 53.45% and mild dysfunction 46.55% (p < 0.05). The range of movement of the knee joint after treatment increased significantly, the average range of movement of the joint at the time of D18 was 129.410 ± 6.470 (p < 0.05). The heel-buttock index decreased significantly: before treatment, the average heel-buttock index was 18.24 ± 6.07 (cm), and after treatment was 8.95 ± 5.33 (cm). There was an improvement in the color, tongue shape, thinness of tongue moss, nocturia symptoms, back pain after treatment (p < 0.05). Overall results: 53.45% good; 44.83% fair; 1.72% average and no poor level (p < 0.05). Conclusion: The electro-acupuncture and San-bi-tang remedy combined with herbal steam in patients of primary knee osteoarthritis is a safe treatment, effectively reducing pain and improving motor function significantly.