Polymerization-induced self-assembly (PISA) was developed to prepare assemblies of conjugated block copoly(phenylacetylene)s for the first time. The living dispersion polymerization of (R/S)-4-(1-phenethylbamoyl)phenylacetylene (rmAN/smAN) can be achieved in the presence of poly(phenylacetylene) (PPA) macro-initiators. The assemblies prepared from the copolymers PPA(m)-b-PrmAN(n) with the short core-forming PrmAN blocks tended to form vesicles in tetrahydrofuran because of the rigid conformation of the block copolymers. As the length of PrmAN blocks increased, the assemblies preferred to form lamellae, and then, the lamellae twisted to form helical ribbons. The helicity of copolymers could transfer to the helical assemblies accurately. This work not only expanded applications of PISA into living coordination polymerization but also enhanced the efficiency of the assembly preparation of rigid conjugated block copoly(phenylacetylene)s.