A case of histoplasmosis at the oral cavity simulating mucocutaneous leishmaniasis is reported. The initial suspicion of leishmaniasis was not confirmed due to lack of amastigotes and no reactivity of the Montenegro's skin test. Diagnosis of histoplasmosis was done by Grocott's stained smears and isolation of Histoplasma capsulatum in Sabouraud's-agar slants. Treatment with Amphoterecin B led to complete remission of the lesion.