A simple, precise and reproducible RP-HPLC method has been developed and validated for the simultaneous estimation of Telmisartan (TEL) and Hydrochlorothiazide (HCTZ) in API and Dosage from. The separation was carried out with the Brownlee analytical C18 column (250mm×4.6mm i.d.), having mobile phase Methanol: Acetonitrile: Buffer:: 70:5:25 (v/v/v). Buffer was Ammonium acetate, pH 4.2 was adjusted with Formic acid. Detection was done at 254nm. The calibration curve was found to be linear within the concentration range 30-60μg/ml for TEL and 08-18 μg/ml for HCTZ. The regression data for calibration curve shows good linear relationship with r2 = 0.9989 and 0.9980 for TEL and HCTZ respectively. The LOD for TEL was found 1.59 μg/ml and for HCTZ 0.54 μg/ml. LOQ was found 4.89 μg/ml for TEL and 1.63 μg/ml for HCTZ respectively. The method was validated in accordance with the requirements of ICH guidelines and successfully applied for determination of drug in bulk and Dosage form. Thus, the proposed method can be used successfully for routine analysis of TEL and HCTZ in different dosage form.