We reported two sibling cases of progressive cerebellar ataxia accompanied with muscular atrophy of Charcot-Marie-Tooth (CMT) type. Autosomal recessive inheritance was suggested because of the parental consanguinity and other family history. The first symptom was ataxic gait in their teens, and speech disturbance appeared later. Subsequently weakness and muscular atrophy developed in the four limbs in their thirties or forties. These symptoms slowly progressed. Neurological examinations revealed weakness, muscular atrophy, and disturbance of superficial and deep sensation in the distal parts of all limbs. Deep tendon reflexes were absent in the four limbs. There were no pyramidal tract signs, nor dementia. Sural nerve biopsy demonstrated the axonal degeneration without any findings suggesting hypertrophic neuritis. MRI study revealed marked cerebellar atrophy. Although plasma amino acid analysis showed elevated glutamate levels in both cases, activities of glutamate dehydrogenase in leukocytes was not reduced. Here, we propose a new disease entity of hereditary cerebellar ataxia and sensorimotor neuropathy associated with elevated plasma glutamate levels. Abnormal glutamate metabolism may be related to the pathogenesis of this disease.