The optical properties of composite materials can be adjusted by controlling the constituents and morphology of the composite structure. The optical nanocomposite approach offers opportunities to produce high-performance and relatively low-cost optoelectronic media suitable for many applications. In this paper, a nanocomposite material obtained by a high niobium content glass belonging to the K2O–Nb2O5–SiO2 (KNS) glass-forming system is prepared and characterized. We focus on the investigation of spontaneous and stimulated Raman scattering. Strong changes of Raman spectra in nanocomposite material with respect to bulk sample are proved and discussed, while a significant enhancement of Raman gain (up to 25 times higher) and of its bandwidth with respect to SiO2 glass is reported. This family of glasses is a promising candidate for next generation Raman gain applications for use in the format of …