Drakshasava is one of the commercial Ayurvedic medicines from India, prepared from grapes and spices. It is believed to address health imbalances and claimed to be beneficial for weakness, bleeding disorders, and various inflammatory diseases. It has been reported to possess pharmacological activities such as diuretic, cardioprotective, and antimicrobial. Being a polyherbal mixture, it faces challenges in its standardization and quality control. The aim of the present study is to develop a validated UPLC-MS/MS method for simultaneous quantification of 10 polyphenolic biomarkers in Drakshasava. It explores the effect of Vitis vinifera L. and additional herbs on fermentation with respect to bioactive compounds through the successive addition method. The MS methods were optimized in multiple-reaction monitoring (MRM) mode with ESI while chromatographic separation was achieved on an Acquity UPLC BEH C18 column using both isocratic and gradient elution in water and acetonitrile containing 0.1% formic acid. The developed method was validated as per ICH-Q2B guidelines and found to be within the assay variability limits. Gallic acid was found to be the most abundant marker in all the samples followed by resveratrol. The content of all the markers has been found to be increased significantly post-fermentation, compared to decoction except kaempferol. The successive addition of prashpeka drvya (minor herbs) in the formulation showed variability at different stages with respect to the selected markers and did not exhibit major changes in the chemical profiling of the final product. The developed method was found to be rapid, accurate, reliable, and highly sensitive for the simultaneous quantification of selected biomarkers in Drakshasava. The research is the first chemometric report on the standardization of Drakshasava by validated UPLC-MS/MS method. It may prove to be a useful tool for the development of new phytopharmaceutical drugs and further quality control of other polyherbal formulations.