This article reports on a novel methodology for preparing a new class of core/shell nanoparticles. The nanoparticles consist of a unique core (composed of an optically active helical-substituted polyacetylene) and a shell (composed of a vinyl polymer) and thus exhibit optical activities. Such nanoparticles were synthesized by combining aqueous catalytic microemulsion polymerization and free radical polymerization in one specific system. The shells could be further cross-linked for improving the properties of particles. The investigations are of high importance not only in polymer chemistry due to the combination of catalytic polymerization and free radical polymerization in one system but also in materials due to the integration of "chirality" and "nano" concepts in one single material.