The aim of the present research was to standardize the indirect immunofluorescence reaction for Endemic Pemphigus Foliaceus (Fogo Selvagem). We found that fresh human skin was the ideal substrate and could proceed from foreskin, head, neck, or anterior abdominal wall. PBS pre-washing of the skin preceding the incubation with the serum should be avoided since the antigenicity might be diminished. TAS-calcium preserves the Pemphigus antigenic properties of the skin and shall be preferred as the diluent for the sera. Albumin-coated slides are useful because they increase the adherence of the skin sections. The conjugate appropriate dilution is convenientely determined by the radial immunodiffusion test (Ouchterlony method). So far as the correlation between the antibody titer and the clinical activity is concerned, we concluded that a titer of 160 or more was of bad prognosis, since it was associated with the generalized form of the disease or with cases of the localized form refractory to the usual therapy. Nevertheless, this assumption needs confirmation by further studies involving an appropriate clinical approach.