The experimental IR (in different matrices) and Raman spectra of 4-aminobenzonitrile molecule were recorded. The results were compared with theoretical values. Geometry, vibrational wavenumbers and thermodynamic parameters were calculated using DFT quantum chemical methods. With the help of specific scaling procedures, the experimentally observed FTIR and Raman vibrational wavenumbers were analyzed and assigned to different normal modes of the molecule. The error obtained was, in general, very low. The contributions of the different modes to each wavenumber were determined using potential energy distributions (PEDs). Other general conclusions were also deduced. Copyright © 2006 John Wiley & Sons, Ltd.