A variety of pulmonary complications, including infection and neoplastic and inflammatory diseases, commonly develop in patients with acquired immunodeficiency syndrome. Nonspecific interstitial pneumonitis, one such complication, is not uncommon, and is very difficult to differentiate, clinically and radiologically,from Pneumocystis carinii pneumonia. We describe a case of nonspecific interstitial pneumonitis, including the chest radiographic and HRCT findings, occurring in an AIDS patient and involving complications.