An aggregation induced emission dye (PhENH₂) with vinyl and amino end-groups was facilely incorporated into stable cross-linked fluorescent polymeric nanoparticles (FPNs) via reversible addition–fragmentation chain transfer polymerization and subsequent ring-opening condensation. Thus obtained FPNs showed high water dispersibility, uniform size, strong fluorescence, and excellent biocompatibility, making them promising for cell imaging applications.