Giant cell arteritis (GCA) and Takayasu arteritis (TA) are both chronic granulomatous vasculitis of unknown aetiology that involve large vessels. Signs and symptoms are related to the affected vessels: the primary branches of the aorta in TA and the extra-cranial branches of the external carotid artery in GCA. TA affects women under 40 of all ethnic origins with a greater prevalence in Asia, whereas GCA affects elderly of caucasian ancestry. In both diseases the diagnosis and follow up are rendered difficult by the absence of specific marker but advances in imaging technologies such as angio-MRI and PET/CT are very promising. Corticosteroids still represent the basis of treatment, most often alone in GCA and usually in association with another immunosuppressive drug in TA.