The 11th International Conference on Phonon Scattering (Phonons 2004) was held in St. Petersburg, Russia, 25-30 July 2004. Both theoretical and experimental results on studies in phonon physics and related phenomena were presented and discussed. Main topical areas were: Phonons in nanostructures, coherent phonons, phononic crystals and superlattices, ultrafast acoustics, solitons and nonlinear phenomena, electron-phonon interaction, phonons in glasses and disordered materials, phonon transport and imaging, quantum fluids, lattice dynamics, and Raman and neutron scattering.