The effect of the zinc acetate molarity combined with the substrate temperatures of ZnO:F thin films deposited by spray pyrolysis, on their physical properties, was studied. The main interest was to optimize the resistivity and the optical transmittance of films deposited at different substrate temperatures. It is to be remarked the influence of the aging of the starting solution on the improvement of the electrical properties of the films. The lowest value of the resistivity was obtained with solutions of 0.2 M. In this case, the resistivity obtained for a film 325-nm thick was 5.5 X 10(-2) Omega cm, decreasing to a value of 6.7 x 10(-3) Omega cm for films 1400-nm thick. Mobility values were approximately 7 cm(2)/V-S. The transmittance in the visible is near 90% at 550 nm. All the films showed a preferred (002) crystalline orientation irrespective of the deposition conditions. Finally, the grain size increased as the molarity of the solution decreased.