Multiple flaccid bullae, erosions, and tense bullae developed in a 67-year-old man with chronic lymphocytic leukemia. A biopsy specimen revealed features of typical pemphigus vulgaris (suprabasilar clefting with acantholysis), paraneoplastic pemphigus (necrotic keratinocytes and hydropic degeneration in addition to acantholysis), and bullous pemphigoid (subepidermal separation and epidermal regeneration). Direct and indirect immunofluorescence studies revealed deposits of immunoglobulins and C3 within the intercellular substance and basement membrane zone in some specimens. Immunoprecipitation of serum revealed four polypeptides with molecular weights of 250, 230, 210, and 190 kd.