This paper reports an optical investigation of Eu 3? :PbF 2 nanocrystals distributed into silica glasses fabricated by sol-gel methods. The sample microstructure was investigated using scanning transmission electron microscopy. The b-cubic PbF 2 crystalline phase was identified using X-ray diffraction analysis. The observed emission bands correspond to 5 D 0 ? 7 F J (J = 0-4) transitions of Eu 3? . The spectroscopic parameters for Eu 3? ions were determined based on excitation and emission measurements as well as luminescence decay analysis. Emission originating from 5 D 0 state of Eu 3? ions in sample containing PbF 2 nanocrystals is long-lived in comparison to precursor sol-gel silica glasses.