Deposition parameters for reactive sputtering of thin films of MoO3 and NiMoO4 were examined with an emphasis of the effect of temperature, O-2/Ar flow rate, pressure, and sputtering power (RF source) or voltage (DC source). Films of alpha- and beta-MoO3 could be produced having oriented structures. alpha-NiMoO4 could only be formed as a multicrystalline film at higher temperatures. Multilayer films of NiMoO4 on alpha-MoO3 were found to include an interfacial material identified as beta-NiMoO4. This metastable material was detected at relatively low temperatures in the bilayer structures.