We describe a subacute spinal subdural hematoma in a patient with psot-traumatic subacute intracranial subdural hematoma. CT and MRI demonstrated hematoma within the interhemispheric subdural space and at the lumbar posterior subdural space which extended from the L1 to the S2 level. The lesion showed high signal intensity on both T1 and T2 weighted images. Surgical decompression of the spinal subdural hematoma was performed. The symptoms completely resolved after surgery. Spinal subdural hematoma may be concomitant with or may occur after intracranial subdural hematoma. If a patient with intracranial subdural hematoma complains of low back pain and weakness in both legs; lumbosacral MR examination should be performed to exclude spinal subdural hematoma.