The infrared spectra of toluene, toluene-α-d3, m-xylene, and m-xylene-αα′-d6 have been obtained from 2 to 30 μ for the vapors and liquids. The Raman spectra of the liquids have also been obtained photoelectrically together with depolarization ratios. Vibrational assignments have been made for the four molecules consistent with vapor band contours, polarization data, the Teller Redlich ratio rule, and a modified ratio rule due to Fitzer and Scott.