The etiology of Behçet's disease, a systemic vasculitis, is unknown. Vascular involvement may be seen in 25% of patients with Behçet's disease. Vasculitis make the prognosis of Behçet's disease severe. The aim of this study is to examine the structural and functional changes and relations of these changes with progression and prognosis of Behçet's disease. For this purpose, 40 patients with Behçet's disease and 40 healthy volunteer control subjects were analyzed, additionally patients with Behçet's disease were divided into 2 subgroups as those with vascular complications and those without vascular complications. Intima-media thickness and arterial distensibility were measured in all subjects with carotid artery ultrasonography. Carotid artery distensibility was significantly lower in the patient group compared to the control group (0.67 ±0.2, 0.93 ±0.4, p<0.05), and carotid artery IMT was significantly higher (0.59 ±12, 0.80 ±0.11, p<0.05). A statistically significant increase in IMT has been detected (0.77 ±11, 0.86 ±11, p<0.05) in patients with Behçet's disease with vascular involvement compared to patients with Behçet's disease without vascular involvement, arterial distensibility in patients with vascular disease was similar with those who has no vascular disease (0.69 ±0.25, 0.63 ±0.25, p>0.05). There was a significant negative linear regression between arterial distensibility and systolic blood pressure (SBP) (B=−1×10−2, p<0.05), and a significant positive linear regression has also been found between IMT and SBP and diastolic blood pressure (DBP) and pulse pressure (PP) (B=6.8×10−3 for SBP, p<0.05, B=6.9×10−3 for DBP, p<0.05, B=6×10−3 for PP, p<0.05). As a result, IMT increases and AD decreases in patients with Behçet's disease compared to results in the control group. Although more studies are required for this subject, use of noninvasive parameters such as IMT and AD, which reflect the structural and functional characteristics of vasculature, may be useful to define disease progression and subjects at high risk.