In addition to hypercholesterolaemia and smoking, hypertension, a chronic disease with many cardiovascular complications, is one of the major risk factors for cardiac ischemia, and the main risk factor for cerebrovascular disease. To elucidate the role of oxidative stress and lipid peroxidation in hypertension and the effect of different medical therapies on these parameters.The present study included measurement of serum lipid profile, total lipid peroxidation and oxidized HDL ( Ox-HDL)in 69 patients aged 30-70 years . They were three groups according to the type of therapy: atenelol ,captopril & no pharmacological antihypertensives NPAHT. The results were compared with those of 45 apparently healthy controls(age range=30-66 years). The results showed a significant elevation in serum MDA and the OX.non-HDL % with a significant reduction in the reduction in the OX.HDL % as compared to the controls. The disturbance in the oxidant / antioxidant balance happened despite the treatment and blood pressure control showing different pictures with different modalities of treatment, being the best with the captopril.