Central nervous system demyelination has been described in adults but not in children with chronic inflammatory demyelinating polyneuropathy. We describe a patient with clinical and electrophysiological features consistent with chronic inflammatory demyelinating polyneuropathy who presented at age 5 with an intramedullary spinal cord tumor-like lesion and at age 8, represented with cerebral and spinal demyelinating lesions. Her clinical course and magnetic resonance imaging features were atypical for multiphasic disseminated encephalomyelitis and indistinguishable from multiple sclerosis. To our knowledge, this association has not been previously described in the English literature in childhood.