Ten patients who survived an acute episode of the adult respiratory distress syndrome were studied on recovery. Serial pulmonary function tests performed in 3 subjects revealed a tendency toward normalization of values at 4 to 6 months after the episode, with a subsequent serial decrease in maximal mid-expiratory flow rates, and a partial reversal by bronchodilators. Of the 10 patients, 6 had dyspnea on exertion and all but one of the 6 were smokers. The ventilatory tests revealed a predominantly restrictive pattern in 2 patients and an obstructive pattern in 4. The 4 asymptomatic patients had essentially normal pulmonary function. Pathologic features of the lung, available in 3 cases, are discussed.