Gp43, the major 43-kDa antigenic glycoprotein of Paracoccidioides brasiliensis, or its 15-amino acid inner peptide (P10), induces a T-CD4+, Th1 cellular immune response which protects BALB/c mice from intratracheal infection by virulent yeast forms. We investigated whether DNA vaccination using the gp43 gene could elicit protective immunity against P. brasiliensis. Animals immunised intramuscularly (i.m.) or intradermally (i.d.) with plasmid DNA containing the gp43 gene induced a specific, long lasting humoral and cellular immune response. A mixed Th1/Th2 cellular immune response in DNA-immunized mice was modulated in vivo by IFN-γ and was protective in BALB/c mice. A significant decrease in the lung colony forming units (CFUs) and reduced, or no dissemination to the spleen and liver of immunised mice were observed.