A base NaY zeolite was exchanged to similar extension for various rare earth elements (La, Nd, Sm, Gd and Dy), and the resulting catalysts were evaluated with reference to hydrogen transfer properties by means of the conversion of cyclohexene at 300 degrees C in a fluidized bed batch reactor An index was defined using the corresponding kinetic constants of a simple lumped model to show that the relative importance of the hydrogen transfer reactions increased linearly as a function of both Bronsted acidity of the catalysts and ionic radius of the rare earth element considered. The differences observed in the effect of the various rare earth elements on hydrogen transfer were moderate, but they suggested that a certain degree of catalytic control can be exerted on these reactions through the selection of the rare earth elements to be loaded into commercial catalysts.