To evaluate bronchial reactivity to methacholine in human immunodeficiency virus (HIV) infection, we submitted 25 HIV-seropositive subjects without full-blown AIDS and 25 HIV-seronegative subjects, all inmates in a drug rehabilitation center for previous intravenous drug abuse, to interview and to bronchial challenge with methacholine. Four (16 percent) HIV-seropositve and three (12 percent) HIV-seronegative subjects noted bronchospastic symptoms. Baseline FEV1 and MEF50 percent were within the normal range in every patient. Bronchial hyperreactivity to methacholine (PD20FEV1 < 1,400 micrograms) was found in two (8 percent) HIV-seropositive and in four (16 percent) HIV-seronegative subjects, with no significant difference in the frequency between the two groups. We conclude that HIV infection without AIDS in intravenous drug users does not appear to be associated with an increased frequency of bronchospastic disorders and to bronchial hyperreactivity to methacholine.