Olmesartan Medoxomil and Hydrochlorothiazide can be estimated simultaneously in commercial formulations using a straightforward, quick, precise, and accurate reverse phase high performance liquid chromatography approach. A Protocol C18 ENDURO Column (250 × 4.6 mm ×5µ), with a mobile phase composed of Acetonitrile and Water 50:50 v/v, was used to estimate the concentration of the medicines in this combination. At 270 nm, the separation was seen while the flow rate was 1 ml/min. OLM and HCTZ had retention times that were, respectively, 1.4 and 1.9 minutes. For OLM and HCTZ, it was discovered that the technique was linear over the range of 10–50 µg/ml. The technique was successfully used to estimate commercial formulations after receiving ICH guideline validation