Over a ten-year period, arthroplasty of the ipsilateral shoulder and elbow was performed in thirty-five extremities of thirty-one patients who had advanced rheumatoid arthritis. The results of the procedures were retrospectively reviewed to determine the appropriate sequence of surgery and the functional results that were obtained. All patients were followed for a minimum of two years after the last arthroplasty. The elbow had been operated on first in twenty-one extremities and the shoulder had been operated on first in fourteen. The time-interval between arthroplasties was significantly longer (p less than 0.005) when the elbow had been operated on first (forty-five compared with 13.4 months). All motion of the elbow and elevation and external rotation of the shoulder improved significantly (p less than 0.005), similar to the improvement in motion that is noted when either joint is operated on alone. Also, there was a highly significant reduction in pain and improvement in function (both, p less than 0.001). Review of the roentgenograms of twenty-three patients demonstrated no humeral fractures or interference in the proper placement of the humeral component of the prosthesis either by the stem of the other prosthesis or by the methylmethacrylate. All of the arthroplasties of the shoulder that were performed as the second arthroplasty were done at least five months after the arthroplasty of the elbow, and no dislocations or subluxations of the components of the elbow prosthesis occurred.(ABSTRACT TRUNCATED AT 250 WORDS)