Coinfection T. cruzi/HIVoccurs mainly in patients who acquired Chagas disease in endemic areas through vector transmission. The expansion of the HIV epidemic to periurban and rural areas and the urbanization of Chagas disease to nonendemic areas have impact on the prevalence of this coinfection. Reactivation of Chagas disease is considered an AIDS-defining condition in Brazil since 2004, and it is associated with severe meningoencephalitis or myocarditis, increase of maternofetal transmission of Chagas disease, and a high mortality. Reactivation is immunodeficiency dependent and was observed in 10-20 % of T. cruzi/HIV-coinfected patients.