A stability indicating RP-HPLC method was developed for the simultaneous determination of Spironolactone (SRL) and Hydroflumethiazide (HFM) in pharmaceutical dosage form. Inertsil ODS - C18 (250 mm x 4.6 mm, 5 µm) column and mobile phase of methanol: acetonitrile : phosphate buffer in the ratio of 55:40:05 v/v at a flow rate of 1.0 mL/min was used for separation of the components. The components were detected at a wavelength of 221nm using UV detector. The Spironolactone and Hydroflumethiazide were separated at retention time 4.67 and 6.74 min respectively. The developed method was validated in terms of precision, accuracy, linearity, specificity, limit of detection, limit of quantitation. The range of linearity was found to be 5-30 µg/mL for Hydroflumethiazide and 5-30 µg/mL for Spironolactone. The proposed method was applied to study the stability of the drugs under different degradation conditions such as acid, alkali, peroxide, thermal and photo light. The developed method was found to be simple, sensitive and rapid and hence, It can be adopted in any laboratory for quality control analysis.