Results: According to apnea-hypopnea index (AHI) 44.4% of CAD patients were OSA. After polysomnographic evaluation, the patients were re-distributed as follows: OSA with CAD (n= 12), OSA without CAD (n= 14), CAD (n= 15), and normal (n= 11). Homocystein levels were higher in 3 groups compared to controls. AHI, MDI and desaturation time was higher in three-vessel disease compared to one and two-vessel diseases (p< 0.05). NO levels were correlated with the period of oxygen desaturation (r:-0.45, p= 0.031). The antioxidant capacity did not differ between OSA and healthy groups.