A male farmer, 20 years old, from the countryside of the State of Piauí, developed acute respiratory infection. Despite adequate antimicrobial therapy, his conditions worsened, requiring mechanical ventilation. His X-rays showed diffuse pulmonary infiltrates. His PaO2/FiO2 ratio was 58. Direct microscopy and culture of tracheal aspirates showed the presence of Coccidioides immitis. Autochthonous cases of coccidioidomycosis have only recently been described in Brazil, most of them from the State of Piauí. C. immitis has been isolated from humans, dogs and armadillos (Dasypus novemcinctus), and also from soil samples of armadillo’s burrows. Failure to respond to antimicrobial therapy and a patient’s origin from recognized endemic areas should alert to the possibility of acute pulmonary coccidioidomycosis.