Photoemission (PS) and Auger electron spectroscopy were used to study the formation of Pd silicide in UHV on Si crystals. The Pd depositions ranged from submonolayer coverages to hundreds of Angstroms thickness. AES sputter depth profiles indicate that room temperature Pd–Si interdiffusion occurs over ∠100 Å and that Pd reduces the native Si oxides, with oxygen appearing at the vacuum surface of the evaporated layer. We have been able to separate out the relative contributions of Si and Pd to the silicide valence band by using a wide range of photon energies in the PS studies. The Pd d-bands in the silicide are filled and, due to the strong Pd–Si interaction, are pulled down more than 2 eV relative to Pd metal. In addition, we suggest that the silicide formed at the surface may be more closely related to that of the glassy metals rather than the well-defined (although closely related) Pd2Si compound. Similar results are also obtained for the system of Pt on Si.