Lung cancer infrequently may be associated with human immunodeficiency virus (HIV) infection. This retrospective case-control study was undertaken to determine if there were differences in age, sex, and stage distribution and in survival between HIV-positive and HIV-indeterminate lung cancer patients. We compared 19 patients with both pathologically verified lung cancer and HIV infection proved by serologic study with lung cancer patients with an indeterminate HIV status. All 19 HIV-positive lung cancer patients were men. This was significantly (p = 0.004) different from the 69 percent male preponderance in 1,335 HIV-indeterminate lung cancer patients. Median ages of HIV-positive and HIV-indeterminate patients were 48 and 61 years, respectively. HIV-positive patients were significantly (p = 0.0139) younger. Stage distribution was similar in both groups. Histologic features and smoking were not significantly different between the two groups. Survival data that were available in 16 HIV-positive patients were compared with 32 HIV-indeterminate control subjects matched for stage, age, sex, and race. The median survival was three months in the HIV-positive group and ten months in the HIV-indeterminate cohort. The survival was significantly different (p = 0.002). There were no one-year survivors in HIV-positive lung cancer patients.