Bullous pemphigoid is a bullous skin disease associated with basal membrane antibodies. At present, the first treatment of these lesions is with corticosteroids. In this randomized study we compared the clinical results obtained with methylprednisolone (MePr) in 28 patients and with prednisolone methylsulfobenzoate (MsPr) in 29 patients. Both drugs were administered orally in daily doses of 1 to 1.5 mg/kg bodyweight. Three clinical data were examined: the number of bullous lesions, the intensity of pruritus and the extent of erythema after 5 then 10 days of treatment. After 10 days, the number of bullous lesions had decreased by 83 p. 100 with MePr and by 78 p. 100 with MsPr, and the decrease of pruritus had been significantly more pronounced in the MePr group than in the Ms group (p < 0.05). There had been no difference between treatments in the regression of erythema. Altogether, good results were obtained in 22/28 patients under MsPr (78.6 p. 100) and 18/29 patients under MePr (62.1 p. 100). This raises the question of the value of pharmacokinetic studies not only with these two corticosteroids, but also with prednisone which seems to be better absorbed.