Myelopathy caused by intrathecal chemotherapy has no known pathognomonic features but it is a diagnosis exclusion. A 16-year-old boy with malignant lymphoma(diffuse large cell), who received intrathecal methotrexate developed progressive motor and sensory deficits and quadriplegia below the C7 level. These symptoms were chronologically related to the time since chemotherapy has been begun. He died a month after the beginning of neurologic deficits. Intrathecal therapy of methotrexate in lymphoma must be used with greater caution, especially when neurologic abnormalities are developed during therapy.