Sol-gel zirconia films of various thicknesses were deposited on 316 stainless steel and treated using one of two firing regimes. The resulting effect on the structure of these films was investigated. One set of films were fired using a regime typically employed for thermal barrier coatings, in which each layer was dried at 380 degrees C separately and then the whole film, which consisted of up to 12 layers, was fired to 800 degrees C. A second set of films were prepared by drying and firing each layer in turn following each deposition. Atomic force microscopy and scanning transmission electron microscopy revealed that the former firing regime was detrimental to the film morphology, resulting in cracking and delamination of the films. These films were also found to contain a significant amount of residual carbon before their final firing. Removal of this carbon during the final firing causes shrinkage and induces tensile stress in the film, The morphology of the latter set of films was found to be crack-free and possessed a surface which became smoother with increasing film thickness, All films were found to contain a discrete layer of chromium oxide between the film and the steel substrate.