Auto-immune mechanisms, mostly cell mediated, have been described as the basic abnormality in polymyositis and dermatomyositis. We report here the case of a patient affected with dermatopolymyositis, resistant to therapy, who was treated with corticosteroids and cyclosporin. She presented with an infiltrative, erythematous rash on the neck, eyelids and cheeks and weakness of the proximal limb and cervical muscles. The dramatic and persistent response to cyclosporin obtained in this case represents a clear demonstration of the action of this drug in cases of dermatomyositis.