Menkes disease is a rare progressive neurodegenerative disorder inherited as an X-linked recessive trait. Clinical findings occur as a copper deficiency due to defect in copper absorption and transport. We present a 6-month-old boy with poor head control and hypotonia. His birth history revealed that he was born at 33 weeks of gestation with a weight of 2200 g. He recognized his mother, at 2 months of age, but his motor movements were gradually decreased and hair color was faded in the last 2 months. There was no consanguinity between the parents; his brother, who had similar findings, died at 7 months of age. On physical examination, he was hypoactive and had microcephaly, dry skin, wooly and depigmented hair, and light colored eyes. His motor development was retarded and was accompanied by poor head control and hypotonia. He also had cortical thumbs, hyperactive deep tendon reflexes, and bilaterally positive Babinski sign. The diagnosis of Menkes disease was made by microscopic examination of his hair, which revealed pili torti and trichorrhexis nodosa, and very low plasma copper level (12 μg/dl [N: 85-190]) and hair copper level. We draw attention to the typical hair findings of Menkes disease, which strongly supported the diagnosis.