The computed tomographic (CT) scans of 55 patients with the acquired immunodeficiency syndrome (AIDS) were reviewed for evidence of pulmonary bullous damage. Although the average age of patients in this series was only 37 years, 42% (23 of 55) had CT evidence of pulmonary bullous changes. In contrast, the frequency of bullous changes detected at CT in a comparable number of immuno-compromised patients with acute leukemia was 16% (eight of 50) (P less than .01). CT findings of bullous damage included bullae or cystic spaces, areas of low attenuation, and vascular disruption. A visual scoring system was used to grade CT scans according to the percentage of lung demonstrating bullous change. Of the 23 AIDS patients with CT evidence of pulmonary bullous damage, 16 (70%) had one or more documented pulmonary infections, while three (13%) had no prior history of lung infection (P less than .05). Spontaneous pneumothorax was a complication of pulmonary bullous damage in three patients. Destruction of pulmonary parenchyma in patients with AIDS may represent the response of the lung to repeated infection.