In an attempt to investigate the effects of treatment of human leishmaniasis, the cytokines produced by peripheral blood mononuclear cells (PBMCs) of patients with cutaneous leishmaniasis (CL) and mucocutaneous leishmaniasis (MCL) under treatment with amphotericin B were determined during the active disease from cocultures of cells and Leishmania (Viannia) braziliensis antigens. PBMC of these patients exhibited a nonsignificant marginal increased production of TNF-α upon antigen stimulation. However, under the same antigenic stimulus, patients with active MCL presented higher IFN-γ production compared to patients with CL. This increased IFN-γ production was accompanied by a drastically augmented IL-12 synthesis from cells of MCL patients. The highlighted T cell responses could be relevant for sound control measures of protozoan infections with emphasis on the combined usage of immunoenhancing agents and antiprotozoal drugs.