The main objective of the given study is that to develop and validate stability indicating reverse phase HPLCmethod for the simultaneous estimation of combined Omeprazole and domperidone in solid dosage forms. The method was optimized Shimadzu RP-LC (HPLC) system with a SPD 10A UV detector (BDS C18 column (250×4.6mm I.D Hypersil). methanol and ammonium acetate buffer (60:40). Methanol is used as diluents. The flow rate is 1ml/min and the effluent is monitor at 280nm. Results: The retention time of combined Omeprazole and domperidone was 6.75min. and 9.64min. respectively. The proposed method study was simple, precise,rapid, accurate and. It was economical and suitable for continuous determination of combined Omeprazole and domperidone in pharmaceutical dosage form. For RP-HPLC, separation of components were achieved at a Phenomenex Rp‐C18 column. The components detected by UV detection at range of 295nm. Thus, the evaluation method is applicable for regular determination of combined omeprazole and domperidone in pharmaceutical formulations.The drugs were placed to different adverse conditions like acid, base, neutral hydrolysis, oxidation, and photo-degradation. The validation of developed method was successfully applied to the simultaneous evaluation of combined omeprazole and domperidone by Reverse Phase-High Performance Liquid Chromatography. Report by RP-HPLC were good assumed.