A simple precise, accurate Reverse phase High performance liquid chromatographic method has been developed for the estimation of Eprosartan Mesylate in bulk. In this method a C18, 25 cm 5μ 4.6 mm ID (Oyster) column with mobile phase consisting of Sodium acetate buffer pH 3.0: Acetonitrile (70:30) was used. The detection wavelength is 235 nm and the flow rate is 1.0 ml/min. The linearity of Eprosartan shows regration coefficient of 0.9999. The proposed method is sufficiently selective to distinguish the parent drugs and the degradation products after hydrolysis photolysis or chemical oxidation.