This paper reviews the precise synthesis of architectural polymers by methodologies utilizing either chain-end- or in-chain-functionalized AB diblock copolymers as efficient key building blocks. Architectural polymers herein synthesized are miktoarm star-branched polymers, exact graft copolymers, high-density comblike polymers, and alternative and sequential multiblock copolymers. Chain-end- and in-chain-functionalized AB diblock copolymers and, in some cases, core-functionalized ABC star-branched polymers utilized as building blocks are prepared by living anionic polymerization in conjunction with specially functionalized agents and linked in manners suitably designed for each architectural polymer to successfully synthesize such structurally complex polymers. The resulting polymers are all well-defined in structure and precisely controlled in chain length.