Nanoparticles (NPs) formed from hyperbranched polymers are highly attractive organized structures in nanomedicine. Herein, we utilize copper-catalyzed azide-alkyne cycloaddition of hyperbranched poly(arylene oxindole) derivatives to prepare amphiphilic conjugates with different degrees of PEGylation that form spherical NPs in water with tunable particle diameters (25 ± 5 nm for PEG0.3-NPs and 120 ± 10 nm for PEG0.1-NPs) and zeta potential (−7 ± 2 mV for PEG0.3-NPs and −23 ± 3 mV for PEG0.1-NPs). (441 characters)