Thin films of ZrO2 have been developed by hydrothermal process on pre-oxidized stainless steel (SS) surfaces composed of different oxides like spinels or alpha-Fe2O3. Variations in thicknesses and uniformity of ZrO2 films have been observed on different pre-oxidized SS surfaces. Raman scattering spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and X-ray diffraction techniques have been used to explain mechanisms of formation of ZrO2 films on various pre-oxidized SS surfaces. A pre-oxidized layer of alpha-Fe2O3 seems to be an ideal oxide on the SS surface for uniform coating of ZrO2. This may be attributed to close match of lattice parameters of ZrO2 with that of alpha-Fe2O3. (C) 2013 Elsevier B. V. All rights reserved.