The alpha,omega-end-capped poly(2-methyl-2-oxazoline) (C-n-POXZ-C-n) have been synthesized by a one-pot process using cationic ring-opening polymerization with an appropriate initiator and terminating agent. The polymers bearing different alkyl groups C-12 and C-18 have molecular weight in the range of 2.4 x 10(3) to 14 x 10(3) with a small polydispersity index. The solution behavior of the free chains has been analyzed in a nonselective solvent, dichloromethane, by small-angle neutron scattering and dynamic light scattering. These amphiphilic polymers associate in water to form flower-like micellar structures. Critical micelle concentrations, investigated by fluorescence technique, are in the range of 0.03-0.5 g L-1 and are dependent on the hydrophilic/lipophilic balance. The structural properties of the aggregates have also been investigated by viscometry. Intrinsic viscosities of these polymers are in the same range as that of the precursors poly(2-methyl-2-oxazoline) (POXZ) and mono-functionalized polymers. Large viscosity increase corresponding to intermicellar bridging was observed in the vicinity of the micelle overlap concentration. Addition of hydroxypropyl beta-cyclodextrin (H beta CD) has dissociated the aggregates and the intrinsic viscosities of the H beta CD-end-capped chains have become comparable with the ones of POXZ precursor chains. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2477-2485, 2010