The study was conducted to evaluate the anti-atherogenic potential of losartan and to assess the effects of hydrochlorothiazide and indapamide on losartan activity in rat. Cholesterol diet (0.5%) for 12 weeks led to significant hyperlipidemia, increased body weight and oxidative stress in erythrocyte. While, losartan, hydrochlorothiazide and indapamide treatment continued for next 12 weeks, losartan showed anti-atherogenic activity reflected by hypolipidemic effect and antioxidant effect in erythrocyte. This activity was abolished by addition of hydrochlorothiazide with losartan but remained unaltered byaddition of indapamide with losartan.