The influence of the amount of a clay binder (sodium bentonite) on the properties and performance of beta zeolite based catalysts for the hydroisomerization of n-octane was studied. The contribution of the bentonite to the total acidity of agglomerated catalysts was very low, although its presence could affect to the acidic properties. Experimental acidity values for the agglomerated catalysts did not match with those theoretically expected due to a solid-state ion exchange between protons of the zeolite and sodium of the clay during the calcination following the ion-exchange step. Metal dispersion values were in agreement with the specific surface area of the zeolite in the agglomerated catalysts, suggesting that the metal were mainly located into the zeolite. Catalysts were tested in the hydroisomerization of n-octane. Concerning the agglomerated catalysts, the higher the strong acid site density per gram of zeolite was, the higher the n-octane conversion was observed. Non-agglomerated catalysts, even showing a higher strong acid site density per gram of zeolite, exhibited the lowest n-octane conversion. EFAL species were present on the agglomerated catalysts enhancing their acid strength through a synergetic effect that allowed them to be much more active for the hydroisomerization of n-octane. (C) 2007 Elsevier B.V. All rights reserved.