Cross section data have been compiled from the literature (to the end of 2003) for electron collisions with water ( H 2 O ) molecules. All major collision processes are reviewed including: total scattering, elastic scattering, momentum transfer, excitation of rotational, vibrational, and electronic states, ionization, electron attachment, dissociation, and emission of radiation. In each case we assess the collected data and provide a recommendation of the values of the cross section to be used. They are presented in a tabular form. Isotope effects ( H 2 O versus D 2 O ) are discussed as far as information is available.