Epidermolysis bullosa acquisita (EBA) is an immunologically distinctive disease with characteristic clinical features. These include extreme skin fragility, trauma-induced blisters and erosions, and healing with scars and milia. These clinical features are currently the major means of routinely distinguishing EBA from bullous pemphigoid (BP) and cicatricial pemphigoid (CP). In this study we describe five patients with EBA who presented with or developed clinical as well as histologic and immunohistologic features indistinguishable from those characteristic of BP or CP. At different times during the course of their disease, it closely resembled classic BP or CP and cases of BP or CP with atypical features or evolving features of EBA. To determine how often EBA might present and be misdiagnosed as BP, we reviewed our experience with bullous diseases and screened eighty-five "BP" sera for EBA antibodies. The results of this study show EBA can mimic the clinical, histologic, and immunohistologic features of BP and CP, suggest that a BP-like clinical presentation occurs in as many as 50% of EBA patients, and suggest that 10% of patients referred to medical centers and diagnosed as BP have EBA.