Cu/silica catalysts show promise for the epoxidation of propene by dioxygen at atmospheric pressure. Their performance is comparable to that reported by Haruta et al. in their first paper on propene epoxidation catalysis by nanoscopic Au particles supported on TiO₂. Our materials deliver stable performance in the presence of oxygen, without the need for H₂ addition, with selectivity toward propene epoxide decreasing with increasing temperature. X-Ray photoelectron spectroscopy, Auger spectroscopy, and high-resolution electron microscopy indicate that the active phase is a highly dispersed form of Cu⁰.