Cyclophosphamide has been used in the management of five patients with pemphigus vulgaris and two patients with bullous pemphigoid. All had developed serious side-effects from corticosteroid therapy, such as gastrointestinal bleeding, severe osteoporosis, diabetes mellitus, and depression. The use of cyclophosphamide made possible, in all patients, the reduction of the high maintenance level of corticosteroid therapy. The only side-effects encountered from therapy with cyclophosphamide were reversible alopecia and leukopenia. This preliminary study indicates that cyclophosphamide is an effective agent in the management of pemphigus vulgaris and bullous pemphigoid.