Four patients received hyperbaric oxygen therapy (HBOT): Three patients had nonarteritic central retinal artery occlusion (CRAO); a fourth patient had a CRAO in the right eye (OD) and a branch retinal artery occlusion (BRAO) with macular involvement in the left eye (OS) secondary to giant cell arteritis. The first two patients presented with a one-day history of CRAO, the third patient with a 10-day history of CRAO OD and the fourth patient with a three-week history of CRAO OD and a three-day history of BRAO OS. The initial visual acuities ranged from light perception to counting fingers at 6 feet. The visual acuity and visual field improved in the first two patients with nonarteritic CRAO. Patients 3 and 4 did not improve. There were no complications. Hyperbaric oxygen treatment may be safe and effective in selected patients with nonacute, nonarteritic CRAO.