Five patients with a one- to 12-day history of symptoms secondary to retinal artery occlusion (RAO) were treated with hyperbaric oxygen therapy (HBO2) for one hour at 1.5 ATA. Four patients had been diagnosed with branch retinal artery occlusion (BRAO) and one patient with a cilioretinal artery occlusion. The three patients with macular sparing occlusions had experienced a loss of visual field, and the remaining two patients with macular involvement had marked loss of central visual acuity. All patients improved following HBO2 treatment. There were no complications. HBO2 may be a safe and effective treatment for patients with RAO.