The phase composition of plasma sprayed (8wt%) YSZ was studied using neutron and X-ray scattering. Comparison shows that neutron scattering is superior for analysis of the phase composition as well as for the analysis of the yttria content of the tetragonal phase. The presence of large amounts of the cubic phase are probably often neglected in standard XRD analysis due to scattering-related limitations and the inherent difficulty of the analysis. The importance of this fact needs to be addressed in future studies. The amount of monoclinic, tetragonal, and cubic phases was determined for as-sprayed deposits and for samples annealed at various temperatures. The as-sprayed deposit was composed of metastable phases, and the phase composition on annealing did not change significantly until 1400 °C for one hour. This indicates the relative stability of the phase composition. The influence of the spray distance is not clear, but the resultant phase composition may be related to the deposition temperature.