Bullous skin diseases represent a group of organ-specific autoimmune disorders characterised by binding of circulating autoantibodies to adhesion molecules of the epidermis and the dermo-epidermal basement membrane zone. Binding of these autoantibodies to their antigenic targets results in loss of adhesion between epidermal keratinocytes and at the level of the basement membrane zone. Chronic blisters and secondary painful erosions are the clinical hallmark of autoimmune bullous disorders. Histopathology reveals the location of blister formation and helps to classify the subtype of the bullous skin disorder. Immunofluorescence is crucial for diagnosing autoimmune bullous skin disorders. Tissue-bound autoantibodies are detected by direct immunofluorescence of perilesional skin. Circulating autoantibodies can be visualised by indirect immunofluorescence using tissue substrates such as monkey oesophagus and sodium chloride-split human skin. Most of the autoantigens are available as recombinant proteins, which allows for autoantibody screening by ELISA or immunoblot analysis to confirm the primary diagnosis and, importantly, for immunoserological follow-up of patients.