A model originally developed to predict the viscosity of concentrated electrolyte solutions was adapted to Jit viscosity data of various sugars and sugar mixtures up to very high concentrations. The model was mu(r) = a exp (EX), where mu(r) is the relative viscosity, a and E are parameters (in most cases a was very close to unity). The model was used to describe the concentration dependence of viscosity of sucrose, fructose, glucose, maltose, lactose and corn syrup (having different dextrose equivalent values) solutions up to very high solids concentration. The molecular weight of the sugar was a main factor in determining the value of parameter E, which on theoretical grounds may be somewhat related to the free energy of activation for viscous flow per mole of solute.