Vibrational spectroscopy can be broadly classified into Raman and infrared (IR). These two techniques are complementary to each other as the mechanisms behind these are different. Vibrational spectroscopy provides detail information about the structure of molecules. The advantage of this technique over X‐ray diffraction is that it can be used to probe molecules in solid, liquid or gas phase. This is especially helpful for studying biomolecules as those molecules can be probed in their physiological environment. Over the last few decades, quantum mechanical calculation has become important tool to assign bands from vibrational spectra. Combination of these two techniques has been used widely in the field of chemistry and biochemistry. In this chapter, we review some of the works that combine both of these techniques. A brief theoretical background is given for understanding the principle of these two techniques.