A simple rapid, sensitive, accurate, precise and reproducible high performance liquid chromatographic method has been developed to assay Olmesartan medoxomil in tablet dosage form. The HPLC analysis used a reversed phase Hypersil BDS C₈ (250X4.6mm, 5µm) column and a mobile phase constituted of buffer and acetonitrile (55:45 % v/v). The buffer is composed of 3gm of sodium perchlorate and 3ml of tri ethyl amine in 1000 mL of water and the pH of the solution was adjusted to 3.0 with orthophosphoric acid. The wave length of the detection is 250 nm. The validation data showed that the assay is sensitive, specific and reproducible for the determination of olmesartan in the dosage form. The method is linear from 10µg mL^-1 to 120µg mL^-1. The accuracy of the method was found to be 99.54%. Mean inter and intraday assay relative standard deviation (RSD) were less than 1.0%. The proposed method provided an accurate and precise analysis of olmesartan in its pharmaceutical dosage form.