The influence of the macro-RAFT agent architecture on the morphology of the self-assemblies obtained by aqueous RAFT dispersion polymerization in PISA is studied by comparing amphiphilic AB diblock, (AB)2 triblock and triarm-star shaped (AB)3 copolymers, constituted of N,N-dimethylacrylamide (DMAc = A) and diacetone acrylamide (DAAm = B). Symmetrical triarm (AB)3 could be synthesized for the first time in a PISA process. Spheres and higher order morphologies, such as worms or vesicles, could be obtained for all types of architectures and the parameters that determine their formation have been studied. In particular, we found that the total DPn of the PDMAc and the PDAAm segments, i.e. same overall molar mass, at the same Mn(PDMAc) / Mn(PDAAm) ratio, rather than the individual length of the arms determined a Supporting Information is available online from the Wiley Online Library or from the author.-2-the morphologies for the linear (AB)2 and star shaped (AB)3 copolymers obtained by using the bi-and trifunctional macro-RAFT agents. FIGURE FOR TOC Text for TOC Self-assemblies of linear AB diblock, (AB)2 triblock and (AB)3 triarm star shaped copolymers are prepared by PISA via aqueous RAFT dispersion polymerization. The influence of the macro-CTA architecture on the nano-objects morphology is highlighted.