BaTi1-xZrxO3 thin films have been prepared on Si and Pt/TiO2/SiO2/Si substrates by radio-frequency magnetron sputtering varying the deposition parameters, such as the chamber pressure, the substrate temperature and the gas composition. The films have been probed by Xray Diffraction (XRD), Wavelength Dispersive Spectrometry (WDS), Scanning Electron Microscopy (SEM) and Rutherford Backscattering Spectrometry (RBS). The dependence of their composition, crystallinity and dielectric properties on these parameters was investigated. The films show dielectric susceptibilities up to 130, dielectric losses of 2% and tunabilities up to 17% under 650 kV/cm at 100 kHz. (C) 2004 Elsevier B.V. All rights reserved.