A simple, accurate, precise and stability-indicating RP-HPLC method has been developed and validated for the simultaneous estimation of Telmisartan and Chlorthalidone in fixed-dosage formulation. The separation was achieved on a octadecyl C-18 reversed phase column (Symmetry C-18, 250mm x 4.6mm , 5µ) using acetonitrile:phosphate buffer at pH 6.5 (70:30 v/v) as mobile phase at a flow rate of 1.0mL/min and temperature of 25°C. The UV detection was carried out at 270nm. The retention time of Chlorthalidone and Telmisartan was found to be 5.48 and 13.38 min. respectively. The method has been validated for Specificity, Linearity, Accuracy, Precision and Robustness. The calibration curve for Chlorthalidone and Telmisartan were linear from the range of 1.25-20.01 µg/mL and 8.0 to 128.4 µg/mL respectively. The mean recoveries obtained for Telmisartan and Chlorthalidone were 100.9% and 99.7% respectively. The developed method was found to be Specific, accurate, Precise, Robust and rapid for the simultaneous estimation of Telmisartan and Chlorthalidone in Telmisartan and Chlorthalidone Tablets 80mg/12.5mg.