Controlled/living radical polymerization is an efficient technique for the synthesis of well-defined polymeric architectures, including copolymers, block copolymers, stars, graft, and variations thereof. In this article, we report for the first time the synthesis of a decablock copolymer via a simple and efficient iterative Cu(0)-mediated radical polymerization technique. In this approach, purification is not required between the iterative chain extension steps, as each block formation is taken to full conversion. The final decablock copolymer can be obtained with a yield in mass of similar to 90%. Using traditional controlled/living radical polymerization techniques, including reversible addition-fragmentation chain transfer (RAFT) polymerization, nitroxide-mediated polymerization (NMP), or atom transfer radical polymerization (ATRP), synthesis of decablock copolymer in such high yield is very difficult (and may be impossible) and requires numerous purification steps. The synthesis of the final complex copolymers required the concomitant synthesis of 16 architecturally discrete block copolymers.