Porous silica beads have been coated with a 2-hydroxy-3-methacryloyloxypropyl beta-cyclodextrin polymer by in situ free-radical polymerization in water. This system has been developed for use as a stationary phase in high-performance liquid chromatography. In the conditions used, the coating efficiency is controlled by the initial concentration of the monomer. The polymer coating has been quantitated by thermogravimetric analysis. The stationary phases have also been characterized by means of the nitrogen adsorption/desorption method, energy dispersion X-ray analysis, and scanning electron microscopy to investigate the changes in the porosity, as well as in the surface properties generated by the coating process. Finally, the chromatographic evaluation has been made under normal- and reversed-phase elution conditions.