The effect of the addition of nickel, titanium, and nitrogen on the air oxidation behavior of W-based sputtered coatings in the temperature range 600 to 800 degrees C was studied. In some cases these additions significantly Improved the oxidation resistance of the tungsten coatings. As reported for bulk tungsten, all the coatings studied were oxidized by layers following a parabolic law. Besides WO3 and WOx phases detected in all the oxidized coatings, TiO2 and NiWO4 were also detected for W-Ti and W-Ni films, respectively. WOx was present as an inner protective compact layer covered by the porous WO3 oxide. The best oxidation resistance was found for W-Ti and W-N-Ni coatings which also presented the highest activation energies (E(a) = 234 and 218 kJ mol(-1), respectively, as opposed to E(a) approximate to 188 kJ mol(-1) for the other coatings). These lower oxidation weight gains were attributed to the greater difficulty of the inward diffusion of oxygen ions for W-Ti films, owing to the formation of fine particles of TiO2, and the formation of the external, more protective layer of NiWO4 for W-N-Ni coatings.