The aim of the present work was to develop and validate a simple, efficient, economical RP-HPLC method for the simultaneous estimation of Lisinopril (LIS) and Hydrochlorothiazide (HCTZ) in bulk, dosage forms and in dissolution samples of LIS and HCTZ tablets. Chromatography was performed on Inertsil ODS 3 column (250 x 4.6mm, 5μm) with mobile phase containing 10mM Ammonium acetate: Acetonitrile (80:20% v/v) at a flow rate of 1mL/min and eluents were monitored at 220nm. The retention times of LIS and HCTZ were 3.7min and 7.6min respectively and showed a good linearity in the concentration range of 2-10μg/mL for LIS and 5-25ug/mL for HCTZ with a correlation coefficient of 0.998 and 0.996 respectively. The validation characteristics included specificity, linearity, and limit of detection, limit of quantification, precision, robustness and stability. Validation parameters fulfilled regulatory requirements in all cases. The percent recoveries were ranged in between 98-102, (RSD < 2). The developed HPLC method was successfully used for the simultaneous analysis of LIS and HCTZ in bulk, dosage forms and in dissolution samples of marketed LIS-HCTZ combination tablets.