Influenza vaccination (IV) has rarely been associated with serious adverse effects, such as Guillain-Barré syndrome, systemic lupus erythematosus, rheumatoid arthritis, polymyalgia rheumatica, and vasculitis.1-7 Giant cell arteritis (GCA) is a large-vessel vasculitis, with a granulomatous arteritis of the aorta and its major branches and a predilection for the extracranial branches of the carotid artery.8 To our knowledge, GCA occurring after IV has not been previously reported. We report a case of GCA that developed after IV in a patient who was positive for HLA-DRB1*04, which has been associated with GCA susceptibility.9