Epithelial gold deposits were demonstrated biomicroscopically in 13 of 15 patients receiving gold therapy for rheumatoid arthritis. Only one of six further patients who had received gold therapy in the past showed such deposits. Deposits appeared with a cumulative dose of sodium thiomalate exceeding 100 mg. The earliest appearance was after seven months of therapy and deposits were visible in one subject as long as nine months after therapy had stopped. The density of deposit does not appear to increase over the whole of the dose range, possibly as a result of the effect of epithelial turnover. No symptoms attributable to the deposit were encountered in any patient.