We report the case of a 68-year-old patient with a traumatic spinal subdural hematoma. MRI demonstrated an area of abnormal intensity and a black line in the inner part of the intradural space. We anticipate that MRI will help to make one more confident in the preoperative diagnosis of spinal subdural hematoma. The symptoms completely disappeared immediately after the operation. Spinal subdural hematoma requires immediate surgical evacuation. The prognosis for functional recovery is good if the condition is appropriately diagnosed and treated before development of irreversible paralysis. We recommend MRI to make an early diagnosis and early evacuation of spinal subdural hematoma.