Azathioprine was given to 11 patients with pemphigoid who had been on long-term maintenance therapy with prednisone or prednisolone. In nine of these prednisone therapy was withdrawn and all were maintained symptom-free on azathioprine alone, while in two the dose of prednisone was considerably reduced. One patient who had never received corticosteroids was controlled by azathioprine alone during the initial acute phase of the illness. Since azathioprine acts slowly, it is recommended that corticosteroids should be used together with azathioprine during the acute stage. Thus azathioprine is valuable in long-term management of pemphigoid, particularly in patients showing corticosteroid toxicity or in whom the minimum maintenance dose is dangerously high.