The infrared spectra of CCl3SO2OCH2CF3 were obtained in the gaseous, liquid and solid states and complemented with the Raman spectrum of the liquid. Quantum chemistry calculations using the density functional theory (DFT) were used to predict the most stable geometry and conformation of the studied molecule. The harmonic vibrational frequencies and force field were also calculated. Comparison with related molecules and with the predicted frequencies was used as the basis for the assignment of the observed spectral features. Subsequently, a scaling of the original force field by means of a least square procedure was made in order to reproduce as well as possible the experimental frequencies, leading to a final root mean square deviation of 10.6 cm(-1).