Among the optic neuropathies, anterior ischemic optic neuropathy and inflammatory optic neuritis can both present with acute unilateral visual loss and optic nerve head edema. Differentiating these two common optic neuropathies is important regarding prognosis of visual recovery, recognition of underlying giant cell arteritis, and prognosis and treatment of multiple sclerosis. Classically, anterior ischemic optic neuropathy occurs in the older individual of any gender, without pain, always with optic nerve head swelling, often with an altitudinal or arcuate visual field defect, and usually with poor recovery. Optic neuritis typically occurs in young females, very often with pain exacerbated by eye movements, with optic nerve head swelling in only one-third of patients, and good visual recovery over months. However, there can be substantial overlap between these two acute optic neuropathies, especially as regards age of onset. Neurologists should be comfortable making the distinction between anterior ischemic optic neuropathy and inflammatory optic neuritis, because we are often the "gatekeepers" for various treatments, including immunomodulatory therapy for presumed demyelinating disease.