Giant cell arteritis is a relatively common form of systemic vasculitis, best known for its predisposition to affect the extracranial branches of the carotid artery and associated potential for visual loss. Additional vascular manifestations include stroke, aortic aneurysm or dissection, and even aortic rupture. Cardiac manifestations include coronary artery disease, aortic valve insufficiency, or left ventricular dysfunction, which may occur independently from the valvular disease or hypertension. Physicians need to be vigilant for this disorder, particularly because the tragic end-organ outcomes such as visual loss can be effectively prevented with early use of corticosteroids. We review the pathophysiology and clinical manifestations of giant cell arteritis and present a rationale for diagnosis and therapy for this disease.