Long-term results of trapeziometacarpal (TMC) joint silicone arthroplasty were evaluated. From 1975 to 1990, 90 TMC joint silicone implants were placed in 85 patients with TMC joint arthritis caused by osteoarthritis and inflammatory arthritis. Sixty-two implants in 58 patients were available for follow-up evaluation averaging 16.4 years (range, 10-25 years) with a 10-year minimum. Patient satisfaction; range of motion; grip, key pinch, and tip pinch strengths; and radiographs were recorded. Eighty-four percent of the thumbs had satisfactory results with good-to-excellent pain relief and function. Grip, key pinch, and tip pinch strengths increased. The number of thumb tips able to touch the palmar base of the small finger increased. Subluxation was apparent in 19% of implants but was not clinically important; however, implant fracture occurred in 6% and required revision. None of the 62 implants had frank silicone synovitis. Silicone arthroplasty seems to be a reliable option for disabling TMC joint arthritis and is associated with a high degree of patient satisfaction.