Forty-four patients who had had a total of forty-seven amputations of an upper extremity and who had had a myoelectric prosthesis for more than two years were evaluated retrospectively for the amount of use of the prosthesis, the use of any other prosthesis, and the demographic factors that might be related to use of the prosthesis. The average duration of follow-up was five years (range, twenty-five months to seventeen years). Forty of the forty-four patients also had a conventional prosthesis. Twenty-two patients (50 per cent) rejected the myoelectric prosthesis completely; thirteen (32 per cent) of the forty patients who also had a conventional prosthesis rejected the conventional prosthesis completely. The patients who used the myoelectric device the least were employed in occupations that required high-demand use of the prosthesis (lifting of more than 4.5 kilograms [ten pounds] or repetitive manual labor) or were receiving or seeking Workers' Compensation, or both.