Yttria-stabilized zirconia (YSZ) thin films were prepared on NiO pellets by a vapour-phase reaction using ZrCl4 and YCl3 as metal sources and the NiO substrate as an oxygen source for the reaction. The film obtained was cubic YSZ, and its Y2O3 content was approx. 8 mol%. The effect of the sintering temperature of NiO substrates was examined. A surface-oxidized nickel wire was then used as a substrate, and a cubic YSZ layer was coated over the wire. The substrate (nickel and nickel oxide) was dissolved in aqueous hydrochloric acid, and a hollow YSZ fibre of approx. 100 mu m diameter was obtained.