The influence of indium on the properties of Pt-Re/Al2O3 catalysts used in naphtha reforming is studied. The addition of indium to the Pt-Re/Al2O3 catalyst produces a big decrease of acidity. It also produces an inhibition of the metal function, i.e., dehydrogenation and hydrogenolysis activity. The reaction of n-C-5 isomerization shows that indium addition decreases the total activity of the Pt-Re catalyst but increases the selectivity to the i-C-5 isomers. The selectivity to low cost light gases (C-1-C-3) is particularly decreased. The reaction of n-C-7 reforming showed that addition of indium increases the stability of the catalyst and the selectivity to aromatics, and decreases the production of light gases.