Previous studies have indicated an increase in the adhesion of deposited metal films to commercial polymers when additional carbon‐oxygen bonds were present on the polymer surface. In this work, we report the changes taking place on an oxygen‐treated polystyrene surface following vapor deposition of copper. We first found that atomic oxygen produces a carbon‐oxygen single bond on the polystyrene surface, with the oxygen displacing a hydrogen and either forming an OH group or cross linking two chains. In addition, this bond is strongly perturbed after vapor deposition of copper. The deposition of copper results in the formation of a copper‐oxygen‐polymer complex on the surface, the exact nature of which is still to be determined. The formation of such a complex is consistent with an increased adhesive strength of copper on oxygen‐treated polystyrene.