Observing the efficacy of the gold sodium thiomalate (under the trade name of Tauredon Byk Gulden) during the treatment of 43 patients with rheumatoid arthritis, a certain number of side effects have been noted and registered. The group being tested comprised 43 patients, 8 men and 35 women, average age being 50. The side effects were observed in 14 patients (32.5%), namely in one man and 13 woman, the most frequent being thrombocytopenia (20.8%), serious exacerbation of the disease (16.6%), thrombocytosis and dermatitis (12.5%). The recurrence rate of the side effects during the treatment with the gold sodium thiomalate was greater during the first (14%) and the second month (11.8%) than during the third (4.6%) and the fourth month (2.5%).