Ag- and Er-doped glass films have been synthesized with a combined sol–gel and ion-exchange route. The intro- duction of silver as erbium sensitizer in the film was obtained by ion exchanging Er-doped SiO2–Al2O3–Na2O sol–gel films. The films were subsequently annealed under controlled atmo- sphere to induce the migration and aggregation of the metal ions. Films showed different Er3+ photoluminescence behav- iors depending on silver concentration and aggregation state. The interaction between erbium ions and Ag centers has been investigated and enhancement of the excitation cross section due to the silver sensitizing effect has been demonstrated. The developed synthesis also allowed the realization of erbium- doped channel waveguides by a selective Na–Ag ion-exchange process.