A 60-year-old woman had central retinal artery occlusion (CRAO) presented to the ophthalmology department with a sudden, painless loss of vision. Her initial visual acuity was light perception and she treated with hyperbaric oxygen therapy (HBOT) 4 hours after the development of visual symptoms. Systemic risk factors were not found so she was diagnosed as having idiopathic CRAO. Her vision improved from light perception to 20/50 after the HBOT. Any complications such as neovascularization were not developed until the last follow up visit of 8th months.