The adult respiratory distress syndrome (ARDS) is a form of acute lung injury characterized by arterial hypoxemia, reduced thoracic compliance, normal pulmonary capillary wedge pressure, and diffuse infiltrates on chest roentgenograms. Mortality remains high and has been associated with sepsis, organ failure, age, and predisposing factors. We prospectively identified 215 ARDS patients over 34 months to examine how these factors influence outcome. One hundred two (47 percent) of 215 patients survived. Age 65 years or older was associated with a survival of 34 percent, which was statistically different from the 53 percent survival of those patients younger than 65 years (p = 0.02). Aspiration pneumonia as a predisposing factor of ARDS was associated with a better survival (p = 0.04). Survivors had statistically less organ failure and sepsis than did nonsurvivors (p less than 0.05). Cause of death was determined using the criteria of Montgomery et al for irreversible organ dysfunction. Forty-five (40 percent) of our patients died of respiratory failure (not sepsis). We conclude the following: (1) survival in our ARDS patients is different from previous reports; (2) the cause of death in our ARDS patients is different from that reported by Montgomery et al in 1985; and (3) multisystem organ failure, sepsis, age, and some predisposing factors of ARDS continue to be associated with decreased survival of ARDS patients.