In this paper, we report on the observation of stimulated Raman scattering in silicon nanocomposites, consisting of silicon nanoparticles dispersed in SiO2 matrix prepared by sol-gel method. Using a 1427nm cw pump laser, amplification of Stokes signal, at 1542.2nm, up to 1.4dB∕cm is demonstrated. A preliminary valuation of approximately a fivefold enhancement of the gain coefficient in Raman amplifier based on silicon nanocomposites with respect to silicon and a significant reduction of threshold power are also reported. These results have a potential interest for silicon-based Raman lasers.