Intrathecal administration of methotrexate is one of the standard therapies in the acute lymphocytic leukemia (ALL). Spinal puncture and tapping for intrathecal administration of methotrexate is considered as a routine procedure but this procedure carries risks of spinal hematoma in ALL patients. Spinal hematoma after spinal puncture is an uncommon

condition, but it can occur more often in patients with thrombocytopenic or coagulation disorder. We report 4 year-4 month-old boy of ALL with spinal hematoma leading to paraplegia following lumbar puncture for intrathecal methotrexate treatment. (J Korean Acad Rehab Med 2002; 26: 104-107)