Functionalization of polysulfones by using "Click" chemistry is described for the example of a small fluorescent analyte propargylpyrene. First, PSUs were converted to azido-functionalized polymers by successive chloromethylation and azidation. Propargylpyrene was prepared independently as a fluorescent click component. Finally, the azido-functionalized PSUs were coupled with propargylpyrene with high efficiency by copper-catalyzed azide/alkyne click reactions. The final polymers and intermediates at various stages were characterized by H-1 NMR, FT-IR, GPC, UV-Vis, and fluorescence spectroscopy techniques.