Abstract Dissection or rupture of the aorta accounts for death in 2–8% of women with Turner Syndrome (TS). Dilatation of the root of the aorta, hypertension and bicuspid aortic valve have been reported as predisposing factors for aortic dissection but the underlying pathogenesis of vascular dilation in TS is unknown. Recent papers have revealed that dilatation of the arterial tree in TS extends beyond the aorta to conduit vessels including the carotid and brachial arteries. The distal extent of this dilation is unknown. This finding of widespread arterial dilation appears to represent an unusual ‘vasculopathy’ in Turner's syndrome. In trying to understand the pathogenesis of this vasculopathy, several aspects of arterial wall integrity lend themselves to scrutiny. There may be a defect of composition or remodelling of connective tissue, an inflammatory process or abnormal smooth muscle contractility thinking particularly of the nitric oxide pathway. Such processes can be exacerbated other features of TS including oestrogen deficiency, hypertension and accelerated atherosclerosis.