A simple, selective and precise RP-HPLC method was developed for the simultaneous estimation of Aliskiren Hemifumarate, amlodipine besylate and hydrochlorothiazide in the Bulk and Pharmaceutical Dosage Forms using losartan as an internal standard. The chromatographic separation of the three drugs was achieved on a reverse phase Inertsil-ODS, C18, 100X 4.6 mm, 5µm column using 0.1 M Ammonium acetate buffer (pH adjusted to 5 using formic acid) and Acetonitrile in the ratio of 65:35 v/v with flow rate of 1.0 ml/min with injection volume 20 µL and the detection was carried out at 232 nm. The retention time of aliskiren hemifumarate (ALSK), amlodipine besylate (AMLO) and hydrochlorothiazide (HCT) were found to be 3.90, 5.22 and 1.91 min respectively. The drug products were subjected to stress conditions of acidic, alkaline, oxidation, UV and Thermal conditions. The degradation products were well resolved from ALSK, AMLO and HCT peaks, thus indicating the stability-indicating nature of the method. The linear regression analysis data for the calibration plots showed good linear relationship in the concentration range of 37.5-225.00 μg/ml for aliskiren hemifumarate, 3.125-18.75 μg/ml for hydrochlorothiazide and 1.25-7.50 μg/ml for amlodipine besylate. The developed method was successfully validated in accordance to ICH guidelines. Hence, this method can be conveniently adopted for the routine analysis in quality control laboratories.