BACKGROUND: The authors define orbital infarction as ischemia of all intraorbital and intraocular structures. It is a rare disorder due to the rich anastomotic vascularization of the orbit. PATIENTS: The authors report three patients with orbital infarction with similar clinical presentations: acute blindness, orbital pain, total ophthalmoplegia, and anterior and posterior segment ischemia. RESULTS: Etiologies of orbital infraction syndrome include occlusion of the common carotid artery (case 1), giant-cell arteritis (case 2), and mucormycosis (case 3). CONCLUSION: Three cases discussed in this article illustrate that orbital infarction is a disorder that can occur secondary to different mechanisms such as (1) acute perfusion failure (e.g., common carotid artery occlusion [possibly combined with anomalous orbital anastomotic channels]), 2) systemic vasculitis (e.g., giant-cell arteritis), and (3) orbital cellulitis with vasculitis (mucormycosis). The blindness and retinal and optic nerve damage were permanent, whereas the other signs of orbital ischemia (ophthalmoplegia and anterior segment ischemia) resolved. Therefore, diagnosis of orbital infarction can best be made during the acute phase.