Bullous pemphigoid (BP) is an autoimmune blistering skin disease associated with circulating autoantibodies to the hemidesmosomal antigens BP180 and BP230. We report two cases of therapy-refractory BP adjuvantly treated by tryptophan immunoadsorption. In both patients, this treatment was associated with rapid clinical improvement and reduction in the required corticosteroid dosage. In addition, levels of circulating anti-BP180 autoantibodies decreased markedly. Antibodies that were eluted from the tryptophan matrix bound to BP180 and induced dermal-epidermal separation in cryosections of human skin. Our observations suggest that immunoadsorption may be a helpful adjuvant treatment in severe BP.