The oxidation properties of WSi2formed by laser reaction of electron beam evaporated tungsten on silicon substrates are reported. Both steam and dry oxidation processes are investigated in the temperature range 900–1000 °C. Measurements of oxide thickness versus time show similar behavior for both processes (linear changing to parabolic) with essentially no loss of W observed. Transmission electron microscopy investigation before and after oxidation indicates no decomposition of the films and grain sizes growing from 100 to ≳500 nm.