Horton's disease, also termed giant cell arteritis, mainly affects large-caliber vessels within the territories of the external carotid branches. Of note is that this condition can also involve the eye, central nervous system, digestive tract, respiratory system, as well as the arterial system of the lower limbs, and the heart. The diagnosis is confirmed based on the biopsy of the temporal artery, which is not positive in all cases. PET imaging takes an increasingly relevant place in the diagnostic tree, revealing metabolic hyperfixation of large and medium vessels. Treatment is mainly based on systemic glucocorticoids. Of note is the progressively increasing place of biotherapies in the condition’s management, primarily comprising specific antagonists of the IL-6 receptor.