The fluorescent amphiphilic block copolymer methoxy poly(ethylene glycol) (mPEG)-b-poly(ethyl cyanoacrylate) (PECA)2-(N-carbazolyl) ethyl methacrylate (CzEMA) was synthesized via living oxyanion-initiated polymerization. mPEG-b-PECACzEMA was characterized by gel permeation chromatography, H-1-NMR, and Fourier transform infrared spectroscopy. The results indicate that the polymerization was well controlled with a narrow molecular weight distribution. The mPEG-b-PECACzEMA nanoparticles prepared by nanoprecipitation techniques showed a narrow size distribution with an average diameter of less than 100 nm. The mPEG-b-PECA-CzEMA exhibited a strong carbazole fluorescence. Furthermore, it was found that the fluorescence intensity of mPEG-b-PECA-CzEMA was sensitive to a change in solvent. The results indicate that a subtle change in the state of the polymer micellar association may have altered the state of carbazole groups, which was responsible for the fluorescence emission. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 3575-3579, 2012