We present a 68-year-old woman who developed acute cerebral subdural hematoma (SDH) early after transforaminal lumbar interbody fusion. Four hours postoperatively, the patient complained of headache and nausea. Enhanced cranial computed tomography showed cerebral SDH. Despite no obvious intraoperative dural damage, we suggest that cerebrospinal fluid leakage by incidental dural tear likely caused the SDH. To our knowledge, this is the first report of detected cerebral SDH immediately after spinal surgery in spite of no neurological deficits.