Zirconium oxide films were deposited by metal-organic chemical vapour deposition using zirconium acetylacetonate as the source material. Use of water vapor together with oxygen as secondary reagents ensured the deposition of carbon-free, pure zirconium oxide films. A study was carried out to investigate the phase structure of films grown under different deposition conditions. Metastable tetragonal zirconium oxide was a dominant phase when the deposition temperature was low or the film contained large amounts of carbon impurity. Simultaneous decomposition of zirconium acetylacetonate and yttrium dipivaloylmethane with water vapor and oxygen was used to obtain highly texturized yttria stabilized zirconium oxide films at relatively low deposition temperatures. The dominant phase was changed from tetragonal to cubic as the amount of yttrium within the films increased. A zirconium oxide film grown at 620 degrees C, containing about 6 at.% yttrium, was highly texturized, and consisted of a cubic phase with a = 0.5122 nm.