We measured carotid artery intima-media thickness (IMT), brachial artery flow mediated dilation (FMD), and coronary flow reserve (CFR) in 38 Behcet's disease (BD) patients without vascular involvement, 15 BD patients with vascular involvement, and 35 control subjects. BD patients with and without vascular involvement were similar regarding carotid IMT (0.52+/-0.14; 0.51+/-0.09; 0.46+/-0.09; P=0.051), and brachial FMD (16.3+/-6.8; 16.5+/-9.1). CFR values were significantly impaired in BD patients compared to the controls; however the BD patients with and without vascular involvement were similar regarding CFR (2.66+/-0.45; 2.62+/-0.48; 2.91+/-0.53, P=0.007 with and without vascular involvement and the controls, respectively). Endothelial and coronary microvascular functions are compromised in BD patients without vascular involvement as remarkably as that in patients with vascular involvement.