The dynamics of fluorescent methylmethacrylate-benzazole dye copolymers were investigated in different concentration regimes by dynamic light scattering. In the dilute regime the polymer behaves as typical polydisperse linear chains in good solvent with a dynamics dominated by a single fast mode. In the semidilute regime, the cooperative diffusion coefficient, D-coop and the correlation length, Could be obtained. Above the semidilute regime the intensity autocorrelation functions show two-step decays. indicating the existence of low ran-e correlations. The dye incorporation, even though small, affects the copolymer dynamics behavior in concentrated Solutions if compared to PMMA. which is probably ascribed to a polymer-solvent interaction. (c) 2005 Elsevier Ltd. All rights reserved.