Duchenne/Becker muscular dystrophy is a progressive muscle disease, which is caused by the abnormality of dystrophin. Spina bifida is characterized by paralysis of the feet, with most of the upper extremities not being affected. We report here on the first case of Becker muscular dystrophy coinciding with spina bifida. The muscle biopsy specimens of the patient showed dystrophic changes in upper extremities, but clearly less in lower extremities. The results show that the restriction of excessive exercise is important for dystrophin deficiency disease.