Enthalpies of solution of 18-crown-6 in water-monosaccharide mixtures have been measured at 298.15 K. The values of standard enthalpies of solution of the crown ether are negative for all studied systems but the shape of the solution enthalpy curves differs from one mixed solvent to another. Measurements performed in this work demonstrate the influence of the stereochemical structure of the monosaccharides and their hydration on the enthalpies solution of the crown ether. (C) 2006 Published by Elsevier B.V.