SiO2 thin films have been deposited on a Ti6Al4V based alloy by sol-gel processing using cetyltrimethylammonium bromide surfactant as a template and glycol as an additive. Isothermal oxidation test results show that the oxidation rates of the silica coated specimens were decreased significantly. A thick rutile titania layer, separated from the substrate by a thin alumina layer, formed beneath the silica film. An alumina layer,which contained a minor amount of titania,formed above the silica film. It is deduced therefore that the growth of the multilayered and mixed oxide scales was dominated by both outward diffusion of metal and inward diffusion of oxygen.