Tungsten carbides, beta-WC1-x and WC, molybdenum carbide nitride, Mo(C, N), and molybdenum nitride, MoN, films were prepared by chemical vapor deposition using WF6 and MoF6 with (CH3)(3)N, NH3, and H-2. The reaction of WF6 with (CH3)(3)N and H-2 yielded WC films at 700-800 degrees C and beta-WC1-x films at 400-600 degrees C. This reaction did not give tungsten carbide nitride, probably because of the higher structural instability of the tungsten nitride than the carbide. The interaction of MoF6 with (CH3)(3)N and H-2, however, gave a molybdenum carbide nitride film at 700 degrees C though the crystallinity was lower than that of cubic molybdenum nitride prepared at the same temperature. Cubic molybdenum nitride MoN films were obtained at 500-700 degrees C from the reactions of MoF6 with NH3 and H-2 using Ar as a carrier gas. The powder product obtained at 800 degrees C by the same reaction was composed of cubic and hexagonal MoN phases, while that prepared at 850 degrees C was hexagonal MoN and metallic molybdenum. Molybdenum nitrides contained nitrogen atoms trapped in the grain boundary in addition to those occupying lattice points. Vickers hardness values of the MoN films prepared at 600-750 degrees C were in the range of 1300 to 1400 kgf mm(-2).