The efficacy of chrysotherapy appears to increase with prolonged administration. In patients who were followed for 3 years after gold therapy was started, remissions occurred in 73% of those who continued chrysotherapy. Only 6% of those who stopped gold injections during the first 18 months subsequently developed "spontaneous" remissions, although initially both groups had comparable moderately severe rheumatoid arthritis of 6 to 8 years' duration. Therefore, in the absence of definite toxicity, maintenance gold injections should be continued indefinitely.