Gold treatment was initiated in 98 patients suffering from early-stage rheumatoid arthritis. In 30 patients side effects due to gold therapy were seen during the first follow-up year: proteinuria in 6, allergic symptoms in 23, and thrombocytopaenia in one patient. The serum IgM level was higher in patients with side effects. None of the 33 other parameters studied showed any significant differences between patients with or without side effects.