Oxidative stress is one of the predisposing factors in adult neurological disorders. We have examined the involvement of oxidative stress in child-onset neurodegenerative disorders, and here we review the findings from our analysis. In cases of Cockayne syndrome, the oxidative products of lipids and proteins were increased in the globus pallidus; however, oxidative nucleotide damage that coincided with reduced copper/zinc superoxide dismutase (Cu/ZnSOD) expression was observed in cases of xeroderma pigmentosum, and these patients also presented increased oxidative stress markers in urine samples. In spinal muscular atrophy, lipid peroxidation in conjunction with oxidative DNA damage was observed in motor neurons. Cases of subacute sclerosing panencephalitis presented oxidative nucleoside damage in cerebral cortical neurons at early disease stages, which were subsequently replaced by lipid peroxidation in glial cells of cerebral white matter. In relation to progressive myoclonic epilepsy, oxidative damage to DNA, proteins, and lipids appeared to coincide with cerebral and cerebellar cortical lesions of neuronal ceroid-lipofuscinosis. Patients with Lafora disease also presented an increase in oxidative stress markers for DNA and/or lipids in the brain and urine. These findings imply involvement of oxidative stress in developmental brain disorders; antioxidant agents could prove to be useful for treating patients with those disorders.