Introduction: A fragmentation pathway of valsartan protonated ion proposed based on rational interpretation workflows. Method: The mass spectral data (MS, MS/MS, and MS 3) of valsartan protonated ion, were attained by electrospray positive ionization with flow injection analysis; using liquid chromatography systems hyphenated with hybrid tandem mass spectrometer (Q-trap). Results: The pathway of fragmentation was established using product ions of the protonated ion; elemental composition, molecular structure and mechanism of formation for significant product ions were proposed. A pathway was proposed based on the MS/MS and MS 3 spectral data in combination with basic interpretation rules and rational workflows. Conclusion: Workflow used for data interpretation can be useful for writing the fragmentation pathway, a mechanism for the formation of fragments, and can be applied for mass spectral data interpretation of similar small organic molecules.