A three-year-old Taiwanese boy with Marinesco-Sjögren syndrome is reported. Psychomotor retardation had been noticed since early infancy with hypotonia, muscle weakness, delayed motor milestones and imbalance in sitting and standing. Bilateral visual impairment proved to be congenital cataract. Speech was limited to a few words. The parents were consanguineous, and there are two similarly affected siblings. The brain computed tomography revealed cerebellar atrophy. The evoked potential studies indicated a central origin or brainstem lesion. The histopathologic study of the muscle showed variation in fiber size and regenerating fibers. The patient received intraocular lens implantation and was discharged under a home rehabilitation program.