Penicillamine is a component of the penicillin molecule which was identified in the urine of patients with chronic liver disease who were receiving penicillin for the treament of intercurrent infections. Walshe demostrated its effectiveness as copper chelating agent and introduced it into the treatment of Wilson's disease. In addition, it has been shown to be effective in treatment of cystinuria, heavy metal poisoning, and rheumatoid arthritis. Levamisole is a three-ringed molecule which has been used as broad-spectrum antihelminthic drug. Levamisole is capable of T cell immune enhancer and has variable effects on antibody production, Since immune enhancer may affect multiple cell types, either directly or indirectly, and may operate on the adenylcyclase-cAMP-prostaglandin system, the results of treatment may be complex. Levamisole has been shown to be effective in rheumatoid arthritis by several study. We analysed the 29 rheumatoid arthritis patients who were treated at Deartment of Orthopedic Surgery, Chung Ang University Hospital from June, 1978 to June, 1982; among them 17 recieving penicillamine and 12 recieving levamisole. The results were as follows: 1. There were statistically significant improvement in ESR. But there were decrease in mean WBC and platelet counts in patients recieving penicillamine or levamisole. Hemoglobin was not affected. 2. Side effects led to withdrawal of treatment in 8(47%) patients in the penicillamine group and 5(42%) in the levamisole group. 3. In 17 patients having penicillamine treatment, one patient had complete remission(8%).