The synthesis and the optical characterization of CoFe₂O₄–SiO₂ nanocomposites is reported in this study. The interaction of the nanoparticles with the host matrix in the nanocomposites prepared by sol–gel was investigated using Raman spectroscopy. Samples with different nanoparticle concentrations as well as pure silica samples (used as references) have been investigated as a function of different thermal treatments. Our findings show that the investigated composite samples reveal a competition among Si–O–Si and Si–OH bonds. The Raman data indicated that the CoFe₂O₄ nanoparticles interact with both the silica or silanol groups in the cavities in which they are formed.