The lumbar puncture is considered as a safe routine procedure in widespread clinical use for nearly a century. To the best of our knowledge, intracranial and intraspinal subarachnoid hemorrhage has never been reported as a complication after a lumbar puncture. We presented a case of a 76-year-old woman who fell in a deep coma after a lumbar puncture with diffuse subarachnoid hemorrhage and acute obstructive hydrocephalus on computed tomographic scans. Magnetic resonance imaging studies of the whole spine showed the hematoma spread along the spinal cord upward to the intracranial subarachnoid space. Remarkably, an extravasation of contrast medium presented at the level of L1 through L2, which was subsequently evaluated using the spinal angiography. There was an ongoing bleeding at the terminus of L1 lumbar segmental artery that lay within the spinal cord. Then a transarterial embolization followed and the hemorrhage stopped immediately. This case reminds us that although lumbar puncture is safe and simple, severe potential complication, such as intracranial and intraspinal subarachnoid hematoma, could occur.