A 48-year-old slender woman presented with a rare case of spontaneous intracranial hypotension syndrome manifesting as patulous Eustachian tube. The patient complained of sudden onset of ear fullness and nasal voice as well as typical orthostatic headache. Patulous Eustachian tube was identified by observation of synchronous movement of the tympanic membrane with respiration and swallowing. The diagnosis of spontaneous intracranial hypotension was confirmed by negative cerebrospinal fluid pressure, and typical magnetic resonance imaging and radioisotope cisternography findings. All symptoms completely resolved within a few days after epidural blood patch treatment. Changes in the venous blood distribution led by collapse of the dural sac of the cervical spine in the standing position presumably caused decreased size of the pterygoid venous plexus around the Eustachian tube.