The light-induced graft copolymerization of acrylic acid, methacrylic acid, and 4-vinylpyridine onto poly [bis(4-benzylphenoxy)phosphazene] films to prep are new grafted phosphazene copolymers containing acid and basic functionalities is reported. The process was carried out in monomer/methanol mixtures in the presence of benzophenone or benzoin ethyl ether as photosensitizers by selective excitation of these last species. The yield of the grafting processes was evaluated as a function of the monomer concentration in the reaction medium, type of photoinitiator, and characteristics of the grafted organic monomers. The acid functions inserted in poly[bis(4-benzylphenoxy)phosphazene]-g-poly(meth)acrylic acid grafted copolymers, and the basic groups of the poly[bis(4-benzylphenoxy)phosphazene]-g-poly-4-vinylpyridine substrates were allowed to interact with basic and acid dyes, respectively, to form permanently colored polymeric films. The photoactivity of these films as substrates for the photosensitized production of singlet oxygen was tested.