This volume contains almost all of the 79 papers presented at the Fourth International Conference on Vibrations at Surfaces. The proceedings reflect the significant advances that have been made in the field of surface vibrations since the previous conference on the topic held in 1982. The presented papers showed a tendency of development in new directions, particularly in relation to dynamical effects occurring in atom and molecule-surface interactions. These proceedings cover the field of surface vibrational spectroscopy in such a way as to make the book an asset to those involved in both experimental and theoretical work in this field.