Four cases of congenital, hypotonic-sclerotic muscular dystrophy are presented. The patients showed clinically prominent features described by Ullrich, i.e. congenital muscle weakness, hypotonia, and hyperextensibility of distal joints, contractures of proximal joints, high-arched palate, hyperhidrosis, posterior protrusion of calcaneus, and no progression. Muscle biopsies revealed dystrophic changes. Ullrich suggested that this condition was a new entity, but the disease has received little attention. In the present cases superior intelligence and tendency to recurrent upper respiratory tract infections were stressed as characteristics of this disorder. Insufficient cellular immunity was suspected and this may contribute to the recurrent upper respiratory tract infections and pneumonia often observed. This disease is considered a distinct entity of multisystemic involvement inherited as an autosomal recessive trait.