Sol-gel ZnO films have been annealed at 500 degreesC under different ambients for optimization of the complete growth process and characterized. X-ray diffraction results show that annealed films have similar structural qualities. Photoluminescence studies show that the visible emission is enhanced when annealed in vacuum and nitrogen, the effect is discussed in relation to the radiative transitions related to the trapped charge carriers. The dark I-V characteristics show that the current increases in vacuum and nitrogen annealed films and decreases for the film annealed in air. The UV Photoresponse of the ZnO films was affected by the annealing ambience. (C) 2005 Elsevier B.V. All rights reserved.