Myoglobinuria may follow extreme muscular exertion or disorders that cause muscle necrosis. Dystonia has not been implicated previously. We studied an 8-year-old boy of non-Jewish, Mexican-American descent with autosomal-dominant dystonia musculorum deformans who developed rapidly progressive and severe generalized dystonia, hyperpyrexia, myoglobinuria, and renal failure. Curarization was required. Transient improvement was achieved with tetrabenazine and baclofen, but bilateral thalamotomy was then performed. Patients with severe dystonia should be observed for evidence of myoglobinuria.