Three direct synthetic routes to branched polymers based on poly(acrylic acid) (PAA) are proposed. Three-arm PAA stars were obtained by the "core-first" approach using trifunctional O-alkyl xanthates as reversible chain transfer agents for MADIX solution polymerization of acrylic acid (AA). Chain extension of PAA star precursors with acrylamide afforded double hydrophilic star-block copolymers. Star-like structures consisting of a microgel core were also prepared by the "arm-first" approach using linear chains derived by MADIX and N,N'-methylene-bis(acrylarnide) (MBA) as the linking agent. Finally, polymeric nanogels were synthesized by radical solution radical crosslinking copolymerization of AA and MBA in the presence of a O-ethyl xanthate as a MADIX agent. Up to 15% mol. of MBA could be incorporated without macrogel formation. Core-shell star structures were obtained by chain extension from the xanthate chain-ends present in these polymeric precursors.