Amphiphilic graft copolymers comprising monomeric units of stearyl methacrylate, methyl acrylate, acrylic acid and poly(ethylene glycol) acrylate were synthesized and their properties in aqueous systems characterized. The structures of these copolymers were analysed by Fourier transform infra-red and nuclear magnetic resonance spectroscopies while their molecular weights were estimated by static light scattering. The study of critical micelle concentrations and micellar sizes indicated that the formation of micelles is primarily determined by the hydrophobic/hydrophilic properties of these copolymers. Encapsulation of pyrene (as a drug model) into the micelles was found to be dependent on their stearyl methacrylate content. These copolymers also exhibited a sustained release pattern for pyrene in aqueous solutions and might indicate their future applications as potential drug delivery systems.