||A simple, precise, accurate and rapid reverse phase high performance liquid chromatographic method had been developed for simultaneous estimation of Irbesartan (IRBE) and Hydrochlorothiazide (HCTZ) in bulk and Pharmaceutical dosage form. A Phenomex Luna C-18 column having I’d of 150×4.6 mm and 5µm particle size was used. The method was carried out in gradient program using mobile phase, 0.02M Potassium dehydrogenate orthophosphate: acetonitrile (60:40 v/v) adjusted to pH-3.4 using dilute ortho phosphoric acid. Flow rate was adjusted to 1.0ml/min and effluents were monitored at 224nm. The retention time obtained for Irbesartan and HCTZ was 2.59 & 8.13min respectively. The calibration curves were linear in the concentration range of 100-300µg/ml for Irbesartan and 50-150µg/ml for HCTZ. The developed method was validated in accordance to ICH guidelines.