A procedure for the preparation of homogeneously distributed cadmium sulfide or cadmium selenide nanoparticles within thin mesoporous silica films was developed. It is based on the use of alkyl (ethylene oxide) surfactant as a structure directing agent and the dip-coating technique for film formation. The films prepared are characterized by low surface roughness and developed mesoporosity. The addition of Cd2+ ions to the reaction sol prior to the formation of films, followed by the calcination of films at 623 K and treatment with hydrogen sulfide or hydrogen selenide led to the creation of cadmium sulfide or cadmium selenide nanodispersions. The occurrence of the size-quantization effect confirms the location of the particles within the pores and proves the particle size to be consistent with the pore width of the host. (C) 2003 Elsevier B.V. All rights reserved.