Optically active films in the system, SiO2-TiO2-Er2O3P2O5 have been prepared by acrosol-gel deposition. Crystallisation and morphology features that determine the preparation of transparent films are described and discussed in relation to the experimental conditions. The photoluminescence (PL) behaviour is then studied and discussed in relation to the films composition and to the nature of the crystallographic phases present in the films. It is concluded that concentration quenching and co-operative up-conversion mechanisms quench noticeably the FL. A 20Ti-0.5Er-10P composition is compatible with the preparation of transparent films together with an efficient prevention of these parasitic mechanisms.