Brachial artery flow mediated dilation (FMD) is a validated, noninvasive physiological measure widely used as a research tool to quantify endothelial function. FMD is diminished in patients with several coronary risk factors, coronary artery disease, peripheral arterial disease, stroke, and is an independent predictor of cardiovascular events. FMD represents a useful method for identify asymptomatic atherosclerotic subjects with raised risk of developing atherothrombotic complications and improves with risk-reduction therapy such as antihypertensive or antidiabetic drugs, antiplatelet agents and statins. FMD could be a great usefulness in ischemic stroke such as stroke subtypes classification, prognostic significance in acute phase, and independent predictor for new-onset vascular event after first-ever stroke, but also in other disease such as cerebral haemorrhage, migraine or syncope. In this review article, brachial artery FMD and its role in experimental and clinical practice is extensively discussed.