A case of generalized Pneumocystis carinii infection presented as hilar and mediastinal lymphadenopathy and was complicated by spontaneous pneumothorax. Extrapulmonary P carinii infection in patients with acquired immunodeficiency syndrome is rare, and pneumothorax is even rarer. The purpose of this report is to call attention to these atypical features of P carinii infection in patients with the acquired immunodeficiency syndrome.