Abstract: In order to determine how often epider-molysis bullosa acquisita might be misdia-gnosed as bullous pemphigoid, we screened 128 samples of ‘bullous pemphigoid' sera with BMZ IgG antibodies. Indirect IgG immunofluoresence was performed on the substrates using 1M NaCl to separate human skin through the lamina lucida. The results showed that 102 sera were epidermal staining pattern, nine were epidermal and dermal pattern, eight were dermal pattern, and nine were negative. Among those diagnosed as bullous pemphigoid about 10% were actually EBA patients. The details of how to split the skin were also given.