The bullous diseases have a history as old as that of medicine. Although blisters have drawn the attention of medical caregivers throughout written history, only modern times have seen the origin of a clear classification of these disorders, based initially upon clinical and histologic criteria. Recent work has allowed clear delineation between similar diseases based upon localization of immune reactants and, more recently, molecular targets of autoimmune response or defects of inherited diseases. With a clear understanding of the clinical findings, histologic alterations, immune deposits, and metabolic defects, a clinician can arrive at a correct diagnosis in almost all cases of cutaneous blistering. The application of molecular biology to the study of bullous diseases has led to a more detailed understanding of the pathogenesis of the disorders. New horizons in the bullous diseases include further understanding of the molecular and immunologic mechanisms that lead to blisters. It is hoped that this understanding will lead to exciting new therapies and hope for patients suffering with blistering diseases.