This paper presents preliminary results on Al doped ZnO thin films prepared by the sol-gel method. The thin films were produced by a dip-coater technique on glass substrate, using zinc acetate dihydrate, aluminium chloride hexahydrate, 2-methoxyethanol and monoethanolamine as raw materials. The ZnO thin films were analysed by XRD, Hall effect and SEM measurements. In order to determine the influence of the thermal treatments on the film properties, a set of four different heat treatments (atmosphere and temperature) were studied. All the films are polycrystalline presenting a crystallographic c-axis orientation (002) perpendicular to the substrate. The best results were obtained for films pre-heated at 400degreesC and post-heated for 1 hour in air at 600degreesC, after annealing under a reduced atmosphere of forming gas, where a resistivity of 3.9 x 10(-3) Omegacm, a Hall mobility of 34.1 cm(2)/Vs, a carrier concentration of 4.7 x 10(19) cm(-3) and an optical transmittance of 90% were achieved.