Toxic epidermal necrolysis (Lyell syndrome) developed in a 43-year woman treated with carbamazepine, perazine, and sulpiride for recurrent manic bipolar disorder. Five days after withdrawal of all psychotropic medication her psychiatric illness was exacerbated and a syndrome of lethal catatonia developed which was promptly treated with unilateral electroconvulsive therapy (ECT). Rapid remission of lethal catatonia after the first ECT treatment and of her affective disorder within days was achieved. According to clinical observations of the preneuroleptic era, early improvement of lethal catatonia following ECT may have been supported by concurrent high dose corticosteroid therapy for toxic epidermal necrolysis.