Inelastic and charge transfer scattering of protons by water molecules at collision energies of 27.0 and 46.0 eV have been investigated in a high-resolution crossed beam experiment up to the rainbow scattering angles. Excitation of the stretching (symmetric or asymmetric) and bending mode vibrations within the electronic ground state, X 1A1, of H2O was observed in the proton energy-loss spectra. In the case of charge transfer, formation of H2O+ in the X̃ 2B1 and à 2A1 electronic states was identified in the corresponding H-atom spectra; the vibrational states within the X̃ and à bands were for the most part resolved and, at small angles (θ≤2°), they were found to be nearly the same as in photoionization (symmetric stretch and bending mode excitation within the X̃ state and pure bending mode excitation within the à state). The vibronic transition probabilities deviate, however, considerably from the corresponding Franck–Condon factors in favor of the enhancement of the quasiresonant states. For both the inelastic and charge transfer scattering, state-selected quantities characteristic of the detailed collision dynamics have been derived. In addition, rotational excitation superimposed on the vibrational transitions could be estimated and for both processes it was found to be of the order of 50–100 meV.