Postural headache due to spontaneous intracranial hypotension occurs without any diagnostic lumbar puncture, myelography, cranial or spinal injury, or spinal anesthesia. The clinical characteristics of the syndrome are disappearance of the headache or a notable decrease in its severity with recumbency, the finding of meningeal enhancement and subdural fluid collection on brain MRI, the pleocytosis and the increased CSF protein concentration. We report a case of a 40-year-old woman who exhibited the signs and symptoms of postural headache due to low CSF pressure. Her headache started suddenly at the occiput and radiated to frontal head. Magnetic resonance imaging (MRI) of her brain showed enhancement of the meninges and subdural fluid collection. Intrathecal radionuclide cisternography showed the delayed appearance of the isotope in the cranium and the minimal CSF leak at the left upper thoracic region. Her headache was relieved completely after a lumbar (L2-L3) epidural injection of 12 ml of autologous blood and remained asymptomatic.