Objectives: Behcet's disease is a multisystem disorder characterized by a chronic inflammation including acute attacks and remission periods. Decreased enzyme activity of the antioxidant system and increased levels of free radicals may have important roles in the damage of tissues observed in the disease period. In addition, the atherogenic tendency of serum lipid, lipoproteins, lipid peroxidation levels and endothelial dysfunction accompany the above mentioned findings. As a consequence of these events. different degrees of low density lipoprotein (LDL) oxidation occur in vivo, and then autoantibodies against oxidized-LDL(AuAb-oxLDL) are produced.