(2-Hydroxypropyl)-beta-cyclodextrin (HPBCD), a modified cyclic oligosaccharide, changes the flow behavior of aqueous solutions of a model telechelic associative polymer, hydrophobically end-capped poly(ethylene glycol) (ODU-12), because the inclusion complexation of HPBCD and octadecyl end-capping groups interferes with aggregation of the polymer end groups. The HPBCD-induced decrease in the high-frequency modulus can be well described assuming a 1:1 binding isotherm, but cannot fully explain the decrease in the low shear rate Newtonian viscosity, because HPBCD also strongly decreases the relaxation time. Consequently, besides decreasing low shear rate Newtonian viscosity, HPBCD also extends the Newtonian behavior to higher shear rates as predicted by the free-path version of the transient network theory [Marrucci et al., Macromolecules 26, 6483-6488 (1993)]. (C) 2004 The Society of Rheology.