3-Chloro-2-methylphenyl isocyanate, also known as 1-chloro-3-isocyanato-2-methylbenzene, is an organic building block containing an isocyanate group. Its Raman spectra, infrared spectra, ab initio and density functional theory (DFT) calculations have been reported. 3-Chloro-2-methylphenyl isocyanate, also known as 1-chloro-3-isocyanato-2-methylbenzene, is an organic building block containing an isocyanate group. Its Raman spectra, infrared spectra, ab initio and density functional theory (DFT) calculations have been reported.