Fluorine-doped ZnO (FZO) thin films were deposited onto glass by the spray pyrolysis process, using zinc acetate and NH4F as precursors. The role of F/Zn atomic ratio, in the starting solution, and the substrate temperature were investigated and the optimum deposition conditions have been outlined. The X-ray diffraction analyses of the films show that there is incorporation of F atoms in the film. The FZO films are of polycrystalline nature with a preferential growth along (0 0 2) plane parallel to the surface of the substrate for temperatures higher than 400 degrees C. It is observed that fluorine incorporation in the films affects the grain size, which decreases as the F/Zn atomic ratio increases, for the same substrate temperature. The films are uniform and exhibit an optical transmittance above 85% in the visible region. A critical substrate temperature (425 degrees C) was observed at which the films show an n-type electrical dark conductivity as high as 9 (Ohm cm)(-1) when using a solution flow rate of 16 ml/min and a gas flow rate of 10 l/min.