Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are closely related disorders that affect people of middle age and older, and frequently occur together. With the widespread use of newer vascular imaging modalities, large-vessel involvement (LVI) has increasingly been recognised in patients with GCA and less often in those with PMR. LVI in GCA can result in complications such as aortic aneurysm and dissection, aortic arch syndrome, and limb arteries stenosis, while vascular complications in PMR are exceedingly rare. It is still controversial which patients should be investigated for LVI, and how LVI should be diagnosed, monitored and managed. In this review, we will try to address six important issues regarding LVI in GCA and PMR.