Organic-inorganic hybrid films are prepared via the hydrolysis and polycondensation of tetraethoxysilane in chitosan solutions. It is shown that the composition of reagents, the time of synthesis, the crosslinking of chitosan macromolecules via amino groups by glutaric aldehyde, and the conditions of drying affect structurization of the resulting films. With the use of optical polarization microscopy and atomic force microscopy, it is found that the films contain silica particles with a wide size distribution. The crosslinking of the chitosan matrix by glutaric aldehyde results in the predominant formation of inorganic nanoparticles in the films. A good sorption capacity of the films for copper ions in solutions is found. It increases by a factor of 1.7 as the content of the silica in the films increases to 30 wt %.