Two hundred seventy-three Muscular Dystrophy Association (MDA) clinic directors and codirectors of 167 of the 220 clinics responded to a survey designed to study patterns of use of mechanical ventilation. Ventilatory assistance was recommended and used on an elective basis in 43 of the 167 clinics. In 68 clinics, the policy was to discourage its use, and 62 clinics were managing no ventilator users at the time of the survey. The most common reason given for discouraging ventilator use was poor patient quality of life. Only two physicians who discouraged use of mechanical ventilation were familiar with newly described methods of noninvasive ventilatory aid. The clinic directors were also asked to estimate the satisfaction with life of Duchenne muscular dystrophy (DMD) ventilator users. Eighty DMD ventilator users also responded to a separate and identical life satisfaction survey. The clinic directors significantly underestimated the users' reported life satisfaction. The directors who discouraged ventilator use more significantly underestimated the users' life satisfaction than those who recommended it. We conclude that the MDA clinic directors' estimation of ventilator users' quality of life and satisfaction with life is positively correlated with the likelihood of their discussing and recommending ventilator use to prolong life. Despite the wider recognition and availability of more convenient noninvasive methods of ventilatory assistance, the use of mechanical ventilation by MDA clinics has not changed significantly since 1985.