Seven female patients with classical rheumatoid arthritis (RA), treated successfully with injectable gold salts (Fosfocrisolo ICI, 0.10 g/week, with a serum gold concentration of 200-400 mcg/dl), experienced severe gold side-effects after 3 to 20 months of therapy, requiring their withdrawal from gold despite the good results in both clinical and laboratory findings. Four patients showed mucocutaneous side-effects (2 dermatitis and 2 stomatitis) and three a moderate or severe proteinuria. Renal biopsy was performed in these patients, with a histological picture of membranous glomerulonephritis referable to gold therapy. Remission inducing drug (R.I.D.) therapy being mandatory in patients with a chronic progressive disease, and in view of the previous efficacy of gold salts, the patients were put on oral gold, Auranofin being administered 3 mg b.i.d. Both the mucocutaneous side-effects and the proteinuria ameliorated within 2 to 6 months, and the remission of the disease was maintained. The chemical and pharmacokinetic differences between the above two gold compounds are discussed.