ABSTRACTA simple and precise, reliable, rapid, reproducible reverse phase HPLC method has been developed and validated for simultaneous estimation of Probenecid & Cefadroxil chromatography was carried out on zorbaxcC18 (4.6*150mm, 5um) column using mixture of ACN: WATER (55:45v/v) as the mobile phase at flow rate of 1.0ml for min the detection wavelength carried out at255nm the retention time of probenecid & cefadroxil was 2.061&2.462respectively. The method produce linear response in the concentration range of 10-50µg/ml of probencid&5-25µg/ml of cefadroxil the method precision for the determination of assay was below 2.0%RSD. The proposed method can be useful in quality control of bulk& pharmaceutical dosage form Keywords:  Probenecid, Cefadroxi, Rp-hplc validation