Chest roentgenograms were obtained in 90 episodes of acute asthma in adults coming to an emergency room. Of these 90 roentgenograms, 50 (55 percent) were interpreted as normal, 33 (37 percent) showed hyperinflation, and 6 (7 percent) showed minimal interstitial abnormalities unchanged from previous roentgenograms. One (1 percent) showed a new alveolar infiltrate in a patient with allergic aspergillosis. There was no significant correlation between chest roentgenogram interpretation and hospitalization. Our data show that the incidence of specific abnormalities on chest roentgenogram in adults with uncomplicated acute asthma is low and suggests that the information obtained from the roentgenogram is rarely helpful to outpatient management. Chest roentgenograms probably are indicated only when there is clinical evidence of pneumonia, a complication of asthma, or a pulmonary disorder that mimics asthma.