Bimetallic Au catalysts have been prepared and tested for the direct gas-phase epoxidation of propene using hydrogen and oxygen. Modification of Au/TiO2/SiO2 catalysts with Pt is beneficial for both activity and selectivity. The water-propene oxide ratio decreases upon addition of Pt to a Au/TiO2/SiO2 catalyst, while the epoxidation activity is maintained. Hydrogenation of propene to unwanted propane does not occur at temperatures below 373 K.