Transparent and conducting zinc oxide (ZnO) films have been prepared on glass substrates by atmospheric and low pressure chemical vapour deposition (CVD) using zinc acetylacetonate (Zn(C5H7O2)2) and various oxygen sources such as air, water (H2O) and hydrogen peroxide (H2O2). A resistivity of (4-6) x 10(-3) OMEGA cm and an average transmittance above 80% in the visible range were obtained for undoped ZnO thin films prepared at a substrate temperature of 550-degrees-C using H2O or H2O2. It was found that H2O and H2O, which include hydrogen, were better oxygen sources than an oxygen-containing gas such as air. The deposition rate of ZnO films was controlled by the Zn(C5H7O2)2 temperature. Al-doped ZnO films with a resistivity as low as 4.6 x 10(-3) OMEGA cm were prepared at a substrate temperature of 350-degrees-C by CVD at a low pressure of 60 Torr using aluminium acetylacetonate (Al(C5H7O2)3) as the dopant source.