Hantavirus cardiopulmonary syndrome is an emerging zoonosis in Argentina, which has low incidence but high death rates. No specific pharmacological therapy is available and symptomatic therapy is the only current alternative. This article presents the pathogenesis of hantavirus cardiopulmonary syndrome through a review of clinical experiences in neighbor South American countries, mainly Chile, and the experience acquired at the Infectious Diseases Hospital Francisco Javier Muñiz, Buenos Aires, Argentina. The role of early corticosteroid therapy is discussed taking into account that there is insufficient evidence favoring its use in the hantavirus cardiopulmonary syndrome.