Aim of this work is to detect the expression of eNOS gene in theblood and arterial wall of atherosclerotic occlusive arterial disease patientsas well as normal vessels.This study was carried out on the 40 patients who are sufferingfrom atherosclerotic occlusive arterial disease (23 males and 17females) and 10 patients (10 male) who are had traumatic arterialinjuries as control group. The range of age was 7-95 years for allpatients, 42-95 years for the diseased group (POAD), 7-36 years forthe control group.The results of this study showed there is statistical significance incorrelation between the two studied groups as there is decrease inexpression of eNOS gene in the diseased group than the control group inboth tissue (arterial wall) and blood.