Prolonged periods of mechanically assisted ventilation are reasonably common occurrences, but there are no data regarding outcome for this patient population. We retrospectively reviewed the medical records of 250 consecutive patients with a minimum of ten days of ventilatory support during a five-year period. The overall survival was 39.2% at discharge, 28.6% at one year, and 22.5% at two years. Age and functional status prior to respiratory failure were the best predictors of survival. In addition, patients with postoperative or neurologic disease as the cause of respiratory failure were found to have the highest survival rate while those with cardiac and pulmonary disease had the worst prognosis. Of those patients who survived to discharge, 39.6% were institutionalized (nursing homes) and 32.7% were confined to their homes. Prolonged mechanical ventilation is associated with a limited survival and poor functional status in many who do survive.