We report adenocarcinoma of the lung in seven patients with human immunodeficiency virus (HIV) infection. We compared age, clinical findings and survival data with a sex-matched control group of HIV-negative patients with adenocarcinoma of the lung. Median age of HIV-infected patients with lung cancer was lower than in control patients with lung cancer. The HIV-infected patients had more systemic symptoms and abnormal physical findings than control subjects. Both groups had smoking histories. Laboratory data were similar but control subjects had lower blood oxygen tensions than did HIV patients; HIV patients had more abnormalities on chest roentgenograms and computed tomography scans than did control subjects. All HIV-infected patients were stage IV. Median survival was 4 weeks. For control patients, 50 percent had stage IV disease; median survival was 25.5 weeks. Thus, patients with HIV infection develop lung cancer at a younger age than sex-matched control subjects and undergo a more fulminant course with shortened survivals.