A new, simple and sensitive reverse phase high performance liquid chromatographic (RP-HPLC) method has been developed for the separation and quantification of Hydrochlorothiazide (HCTZ) and Losartan Potassium (LOS) in tablet dosage form. The determination was carried out using GRACE C18 [4.6 x 250 mm] column as a stationary phase and mobile phase comprised of Acetonitrile: Phosphate Buffer(50 : 50) pH 3.1 in proportion of 50:50(v/v); the pH of phosphate buffer adjusted to (3.1) using orthophosphoric acid. The flow rate was maintained at 1.0ml/min and the eluent was monitored at 226nm.The retention time of MET and VILD were 4.250 min and 8.300 min respectively. The method was validated in terms of linearity, precision, accuracy, specificity and robustness. The method was linear and for precision studies; RSD for HCTZ and LOS were 0.02 and 0.04 respectively. The percentage recoveries for both drugs from their tablets were 100.80 and 99.76 respectivel
