BACKGROUND Spinal subarachnoid hemorrhage has many causes including trauma, vascular malformations, aneurysms, spinal cord tumors, coagulation abnormalities, use of anticoagulants, systemic lupus erythematosus, or Behçet's disease. We report on a rare case of a spontaneous spinal subarachnoid hemorrhage after severe coughing of unknown origin. To the best of our knowledge, this is the first report of spontaneous spinal subarachnoid hemorrhage after severe coughing. METHODS A 66-year-old Japanese woman initially complained of headache with severe back pain after severe coughing. She was referred to our neurology department 6 days after her first visit to our hospital. No neurological deficits were revealed except for meningism. Computed tomography of her head revealed no abnormality. A lumbar puncture showed bloody cerebrospinal fluid with xanthochromia. Cerebral angiography revealed no abnormality. Magnetic resonance imaging of her lumbar spine revealed subarachnoid hemorrhage. Spinal angiography revealed no abnormality. The diagnosis of spontaneous spinal subarachnoid hemorrhage was made. She recovered with conservative treatment and her neurological status was normal 2 years after the onset. CONCLUSIONS Spontaneous spinal subarachnoid hemorrhage could be caused by rapid changes in intrathoracic and intra-abdominal pressure. Spontaneous subarachnoid hemorrhage should be considered when sudden back pain associated with severe headache develops. Even though emergent surgical decompression is necessary when the neurological state progressively deteriorates, conservative treatment with close monitoring of the symptoms can be recommended for patients with a stable neurological status.