Cadmium sulfide nanoparticle/polymer composites have been produced using a one-system reverse micellar synthesis. A monomer, methyl methacrylate (MMA), was used as the oil and polymerized following formation of 2-3 nm CdS particles in the fluid medium. When Aerosol OT (ACT was employed as the surfactant, opaque solids containing 20-80 nm aggregates of the CdS nanoparticles were obtained. The aggregates were fairly uniform in size, their diameter depending on the AOT concentration. With a 1:1 weight ratio of MMA and a polyethylene diacrylate, aggregation was eliminated but the solid remained opaque. Replacing the AOT by the polymerizable surfactant didecyldimethylammonium methacrylate with MMA as the oil led to the formation of a transparent solid matrix containing nonaggregated CdS particles.