Biodegradable polymers e.g. poly(lactic acid) (PLA), poly(hydroxyl butyrate) (PHB) or poly(vinyl alcohol) (PVA) derivates, are becoming strong competitors for conventional non-degradable polymer resins for high performance packaging. However, their mostly inferior barrier and thermo-mechanical properties allow only specific functions and short-term packaging films production. Ionic liquids (IL) are organic salts which keep the liquid state at temperatures below 100 °C. They present ionic-covalent crystalline structures with properties such as; insignificant flammability and volatility, high thermal and chemical stability, high ionic mobility and stability in the presence of air and moisture. They also belong to a class of multifunctional surfactants that showed promising antimicrobial properties. The in situ application of IL into sol-gel silica formation processes allows structure control, driven by IL’ self-assembling and selective interaction with substrates while preserving their specific properties. IL interact with the growing system through the hydrogen bond “co-π-π stacking” mechanism, allowing the formation of new organic-inorganic multifunctional materials. Herein we show that the addition of small amounts of homogeneously dispersed multifunctional silica/ionic liquid nanofillers effectively improve the original properties of biodegradable polymer matrixes. Samples were prepared by solvent casting melt-mixing and investigated as for their structural, mechanical and barrier properties. Keywords: Ionic Liquids, Biodegradable Polymers, sol-gel silica.