Eight elderly men and two elderly women presented with symmetrical polysynovitis of acute onset involving most of their appendicular joints and flexor digitorum tendons associated with pitting edema of the dorsum of both hands and both feet. Onset of seven of the ten cases could be pinpointed almost to the hour. Rheumatoid factors were absent from serum samples in all, and no radiologically evident erosions developed. Clinical and laboratory signs of inflammation and the edema disappeared gradually in each case. Treatment consisted of aspirin or other nonsteroidal anti-inflammatory drugs. Hydroxychloroquine, 200 to 400 mg/day, was given in six and gold therapy in two cases. Painless limitation of motion of the wrists and/or fingers persisted in all, although the patients were both unaware of and unhampered by this abnormality. Six of eight cases where typing was possible were positive for HLA-B7, CW7, and DQW2 (relative risk for B7, 9.5). Three cases of this syndrome were found in a consecutive series of 52 men diagnosed as having definite "rheumatoid arthritis," and thus represent a distinctive condition with an excellent prognosis.