This study presents a facile way synthesizing disc-like lipid bilyaer nanostructures with a cationic amphiphilic polyelectrolyte. The cationic amphiphilic polyelectrolyte was in a form of partially quarternized copolymer and was synthesized with 2-(dimethylamino)ethyl methacrylate and stearyl methacrylate. At some concentration ranges of the polymer, the addition of the polymer to lipid components during the preparation of bilayer nanostructures resulted in discs with a fairly high yield (~99%). The mechanism for the formation of the nanostructures was discussed based on the physical properties of these nanostructures and by comparing the nanostructures obtained with an anionic amphiphilic polyelectrolyte.