A series of positively charged imidazolium-functionalized ionic polyurethanes (IPUs) were prepared in one-step polymerization process by polymerization of presynthesized short-chain imidazolium-based ionic diol, polyethylene glycols with different molecular weights as long-chain diols, and toluylene-2,4-diisocyanate. The structures of IPUs are confirmed by 1H NMR analysis, and the thermogravimetric analysis measurement indicates that the IPUs have high degradation temperature. Fluorescent nanocrystalpolymer composites CdTeIPU can be prepared conveniently, by the electrostatic interaction between positively charged IPUs and the negatively charged aqueous CdTe quantum dots (QDs). UVvis absorption and photoluminescence spectra indicate the photochemical stability and strong fluorescent emission of CdTeIPU composites. The quantum yields (QYs) of the composites are high and basically restore the QYs of the pure QDs. In addition, the transmission electron microscopy photographs show that the QDs in composites are uniform (about 3 nm in diameter) and monodisperse. The obtained nanocomposites are powder or elastomers with good film building. The casted CdTeIPU films are transparent under visible light, and the colors of the composites and their films are vivid under a UV lamp. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: 509-516, 2012