The authors describe the clinical and radiographic findings of lung carcinoma in six patients infected with the human immunodeficiency virus (HIV). These patients were in a younger age group than is commonly associated with lung cancer. The radiographic findings included mediastinal adenopathy (n = 5), hilar masses with distal atelectasis (n = 3), parenchymal masses (n = 3), pleural effusions (n = 2), and pleural thickening (n = 1). Recognition of any of these findings should raise the diagnostic possibility of lung cancer in this group of younger patients.