We describe here the epidemiological and clinical characteristics of 10 HIV-infected patients with paracoccidioidomycosis. All patients were adult males from small towns in Brazil and had a previous history of work or residence in a rural area. The two infections were diagnosed concomitantly in six of the ten patients, and for six of the patients, the mycosis was the first clinical manifestation of HIV infection. Risk factors for HIV infection were injection drug use in some patients and multiple sexual partners in others. Six patients died and autopsy revealed severe disseminated paracoccidioidomycosis in three. Exuberant and severe clinical pictures suggest an alteration in the natural history of this mycosis as a result of HIV immunosuppression. The frequency of paracoccidioidomycosis in the HIV-infected population is not known to differ from that reported for this mycosis in non-HIV patients.