This is the first book to deal with the effect of vibrational pre-excitation on molecular dynamics, both in the gas phase and on surfaces. In particular, it deals with the influence of this excitation on the dissociation of molecules. The effect in the gas phase has been extensively studied but research on surfaces is new and a very hot topic. The contents include a brief review of other methods for controlling dissociation, experimental methods, vibrational state enhancement and control of photodissociation, vibrational state-resolved dependence of surface reactivity and specific examples in the gas phase and on surfaces. The book finishes with a chapter on ‘The Road Ahead’. It also includes a bibliography and subject index.