Molybdenum has been deposited at room temperature on stoichiometric TiO2 (110) surfaces with two deposition rates: 0.1 equivalent monolayer (eqML) and 1.5 eqML min(-1). X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy studies clearly reveal an effect of the deposition rate upon the growth mode and the interfacial reaction. Indeed, whereas a strong interfacial reaction between Mo and TiO2 involves a Stranski-Krastanov growth mode with the formation of amorphous molybdenum oxide monolayers for the lowest deposition rate, no reaction can be observed for the highest deposition rate. Moreover in this latter case, the growth mode seems to be a 3D one. These differences are discussed from a pure kinetics point of view. (C) 2003 Elsevier B.V. All rights reserved.