Children with spinal muscular atrophy were treated by the administration of thyrotropin-releasing hormone. In three infants with spinal muscular atrophy type I, thyrotropin-releasing hormone showed little efficacy, but in children with types II and III, there was improvement in motor function and electromyographic findings after the thyrotropin-releasing hormone therapy. Thyrotropin-releasing hormone has a neurotrophic effect on the spinal anterior motor neurons of spinal muscular atrophy patients and thus may be warranted for the management of spinal muscular atrophy.