Objective: The objective of the study was to develop and validate a new diffuse reflectance infrared fourier transform (DRIFT) spectroscopic method for the quantification of Tramadol HCl in the pharmaceutical dosage form. Methods: The Fourier Transform Infrared (FTIR) analysis was carried out on Cary 630 FTIR spectrophotometer (Agilent Technologies, USA) equipped with a diffuse reflectance sampling interface (650-4000 cm-1, 32 scans, 8 cm-1 resolution). The solid-state samples were prepared by dilution in dry potassium bromide and were analysed by an FTIR spectrophotometer with the DRIFT sampling technique, which follows the Kubelka-Munk model depicting the theory of diffuse reflectance at scattering surfaces, relating band intensities to concentration for transmission measurements similar to Beer’s law. Results: A linear relationship was found in the selected wavenumber range of 3295-3298 cm-1denoting the carboxyl peak in the concentration range of 0.6-3.0% w/w with a good correlation coefficient of 0.997. The percent recovery of Tramadol HCl in the marketed dosage form was found to be 100.4%. Conclusion: The proposed method was found to be accurate, precise, reproducible, and eco-friendly. DRIFT spectroscopy may have the potential as an alternative method for qualitative and quantitative analysis of Tramadol HCl in its capsules.