Giant cell arteritis (GCA) is a medical emergency characterized by systemic inflammation and critical ischemia. Neuro-ophthalmic complications occur early, with permanent vision loss in up to one fifth of patients. This mainly results from failure of prompt recognition and treatment. Diagnosis of GCA is often preceded by unrecognized symptoms, including constitutional upset and jaw claudication. Features predictive of permanent visual loss include jaw claudication and temporal artery abnormalities on physical examination. These patients often do not mount high inflammatory responses. Modern imaging techniques show diagnostic promise, and have led to an increased recognition of major artery involvement in GCA. However, temporal artery biopsy remains the gold standard for investigation. Intimal hyperplasia on histologic examination is associated with neuro-ophthalmic complications. The mainstay of therapy remains corticosteroids. Experience using conventional disease-modifying drugs has been mixed, and biologic therapies require further evaluation for their steroid-sparing potential.