Behçet disease (BD) is a form of vasculopathy that can influence blood vessels of variable diameters. Endocan is a biomarker of endothelial activation and it is secreted from endothelial cells as a soluble proteoglycan. The aim of the work was to assess endocan serum level in patients with BD and to examine its relationship with disease activity parameters and carotid intima media thickness (IMT). The study encompassed 42 patients with BD (25 males and 17 females) diagnosed according to the International Study Group Criteria of BD and 42 age and sex matched apparently healthy volunteers as controls. Human Endothelial cell-specific Molecule–1 (Endocan) was assessed using ELISA. Carotid mean IMT was calculated by Color Doppler ultrasonography. Thickness measurement more than 1 mm was considered abnormal:BD patients had significantly increased endocan serum levels (median, 249.5; IQR, 174 – 445 ng/l) compared to healthy controls (median, 190.5; IQR, 128 – 235 ng/l, P=0.002), endocan serum level was increased in BD patients with active disease (median, 434; IQR, 246 - 617.5 ng/l) compared to those with inactive disease (median, 195.5; IQR, 145 – 235 ng/l, P