Patients with a suspected diagnosis of giant cell arteritis (GCA) should be started on high-dose corticosteroid therapy without delay. A temporal artery biopsy should be performed after initiation of therapy to confirm the diagnosis. Patients with acute visual or neurologic symptoms present a neuro-ophthalmic emergency. Therapy should be initiated immediately with high-dose intravenous methylprednisolone sodium succinate and followed by high-dose oral prednisone. Treatment may begin with high-dose oral prednisone in patients without visual or neurologic symptoms. Calcium, vitamin D, and peptic ulcer prophylaxis should accompany steroid therapy, as indicated. The following treatments should be considered for patients with suspected GCA and acute visual or neurologic signs or symptoms: intravenous methylprednisolone sodium succinate (250 mg intravenously every 6 hours) should be given for 3 days, followed by oral prednisone (80 mg per day or 1 mg/kg) for 4 to 6 weeks. Prednisone should then be tapered by 10 mg per day every month. Most patients require 1 year of therapy to avoid relapse. Taper and duration should be modified according to erythrocyte sedimentation rate, C-reactive protein, and signs and symptoms of GCA. Rheumatologic consultation and follow-up is often helpful for these patients. For patients with suspected GCA and no acute visual or neurologic signs or symptoms, therapy may begin directly with oral prednisone (80 mg per day or 1 mg/kg) with same taper and duration based on laboratory values and clinical signs and symptoms.