Reflection high-energy electron diffraction (RHEED) operated at high pressure has been used to monitor the growth of thin films of titanium dioxide (TiO2) on(1 0 0) magnesium oxide(MgO) substrates by pulsed laser deposition (PLD). The deposition is performed with a synthetic rutile TiO2 target at low fluence. The topography and structure of the deposited layers are characterized using in situ high pressure RHEED and atomic force microscope (AFM). Based on these observations the growth mode of the films is discussed. The results will be compared to earlier results obtained for the growth of TiN films on (1 0 0) MgO. (C) 2008 Elsevier B. V. All rights reserved.