Measurements of heat transport, as expressed by the Nusselt number Nu, are reported for turbulent Rayleigh-Bénard convection of water containing up to 120 ppm by weight of poly-[ethylene oxide] with a molecular weight of 4x10{6} g/mole. Over the Rayleigh number range 5x10{9} less than or approximately Ra less than or approximately 7x10{10} Nu is smaller than it is for pure water by up to 10%.