Objective: The objective is to study liquid chromatography tandem-mass spectrometry (LC/MS/MS) method for simultaneous quantification of paracetamol (PCM), guaifenesin (GUA), phenylephrine hydrochloride (PE), chlorpheniramine maleate (CPM), and ambroxol hydrochloride (AMB) in tablet dosage form developed and validated as per the International Conference on Harmonization Q2 (R1) guideline. Methods: The chromatograms were developed using a gradient mobile phase of WATER:methanol. Flow rate used was to 0.3 ml/min. Quantitation was performed using multiple reaction monitoring (MRM) mode to study parent to product ion transition, for paracetamol. (m/z 152.0 ≥ 110.0), guaifenesin (m/z 199.0 ≥163.0), phenylephrine hydrochloride (m/z 168.0≥ 150.0), chlorpheniramine maleate (m/z 275.0 ≥ 230.0) and ambroxol hydrochloride (m/z 379.0 ≥ 263.8). Results: The retention times were found to be 1.76, 1.81, 1.90, 2.10, and 2.33 min for PCM, GUA, PE, CPM, and AMB, respectively. The linearity of the method was found to be in the concentration range of 10–200 ng/ml for PCM, GUA, PE, CPM, and AMB. Percentage relative standard deviation values for repeatability and intermediate precision studies were below 2%. Conclusion: Developed method was found to be robust, precise, accurate, rapid and can be used to analyze fixed-dose tablet formulation used in the study.