The possibilities offered by the ring-opening metathesis polymerization (ROMP) of macromonomers were exploited to arrange polystyrene (PS) and polybutadiene (PB) subchains in various topologies. PSn-b-PBm and PSn-co-PBm miktoarm stars were obtained by sequential and statistical polymerization of norbornene-terminated PS and PB macromonomers, whereas (PS-b-PB)(n) star block copolymers were derived by homopolymerization of the corresponding macromonomers via ROMP. Umbrella-type and dumbbell-shaped copolymers are two other architectures that were prepared through the sequential ROMP of omega-norbornenyl PS macromonomer and cyclooctadiene.