We report here on a simple and environmentally friendly procedure for preparing transparent, luminescent ionic liquid-containing poly(methyl methacrylate) (PMMA) ionogels in the form of monoliths, films and flexible self-standing films. Lanthanide oxides and organic ligand were firstly dissolved in carboxyl-functionalized ionic liquids to form a lanthanide complex-containing ionic liquid, which was then dissolved in methyl methacrylate (MMA) monomer without using any organic solvents. The following polymerization process leads to transparent materials (monolith, film and flexible self-standing film) containing ionic liquids, PMMA and a lanthanide complex, which are highly luminescent under UV-light irradiation.