Seventeen patients with classical rheumatoid arthritis have been treated with gold sodium thiomalate(G.S.T) injection and followed up for 1.7 years on average. The results obtained are as follows: 1. Clinical improvement was obtained in 12(70.3%) out of 17 cases, but only in 5 cases(29.3%) marked and persisting improvement was obtained. Such improvement was first noticed when the total dose of the gold sodium thiomalate reached 500mg or more, and also noticed about 10 weeks after initiation of G.S.T therapy. 2. Changes in laboratory parameters such as hemoglobin, hematocrit, eosinophilia, titers of rheu- matoid factor and C-reactive protein, and proteinuria began to appear at the time of the clinical improvement. 3. Adverse reaction consisted mostly of mucocutaneous lesions. The main causes of drop-out during therapy also are severe skin rashes and pruritus. Most of the adverse reactions appeared when the total dose of G.S.T. administered reached over 500mg. In two severe cases skin rashes terminated the gold therapy. Our findings suggest, because of high incidence of adverse reaction during G.S.T therapy, repeated careful clinical and laboratory examination of the patient are mandatory especially when the total dose of G.S.T is reached 500mg. In spite of the well documented reports of the maintenance gold therapy for rheumatoid arthritis it is felt that the maintenance gold therapy should be studied further before it can be safely used as a routine in daily rheumatology practice because of its toxicity.