Three-arm (A(2)B) and four-arm (A(2)B(2)) star-shaped copolymers based on biocompatible and biodegradable hydrophobic poly(epsilon-caprolactone) (PCL) (A arms) and biocompatible and bioeliminable hydrophilic poly(ethylene oxide) (PEO) (B arms) were synthesized by the coupling of an omega-azide terminated PEO chains with PCL chain bearing one (A(2)B) or two (A(2)B(2)) alkyne functions at the middle of the chain by the copper mediated azide-alkyne cycloaddition (CuAAC). The amphiphilic behavior of these different stars was confirmed by micellization experiments in water followed by dynamic light scattering and transmission electron microscopy analyses. The efficiency to stabilize PLA nanoparticles was investigated in function of the stars structure.