Mother Nature produces a perfectly defined architecture that inspires researchers to make polymeric macromolecules for an array of functions. Preparation of a pre-defined polymer architecture is a key challenge to a researcher. The present article describes the recent development in Polymerization Induced Self-Assembly (PISA) to synthesize polymeric nanoparticles with pre-defined morphology and precise control over size and shape. This methodology has become a potential strategy for the synthesis of various block copolymer nano-objects. The PISA strategy produces core–shell polymeric nanoparticles with a wide scope of morphologies including spheres, worms, rods, and vesicles. A few parameters including the degree of polymerization, core-forming monomers, macro-CTA and solid content of the final product are precisely employed for the PISA procedure to accomplish the ideal size and shape. PISA opens a new avenue for the production of polymeric nano-objects.