Gold catalysts supported on TiO2 and TiO2/SiO2 have been studied with 197 An Mossbauer spectroscopy. During the preparation of the Au/TiO2 catalyst the formation of metallic particles is observed. The presence of ionic gold in active gold catalysts is not observed. The spectra can be interpreted in terms of bulk-like contributions from the inner-core atoms plus contributions from the outermost atoms at the surface of the particles.