Pt-HY, Pt-NaHY, Pt-NaY, and Pt-NaX catalysts, which possess decreasing acidity and increasing basicity in the above sequence, were tested at 603 K in n-hexane conversion as a model reaction. Pt-HY and Pt-NaHY, which are acidic, are more active by about an order of magnitude than the two non-acidic catalysts. Selectivities measured at different hydrocarbon and hydrogen pressures are presented as a function of the overall conversion. Pt-HY and Pt-NaHY produce mainly skeletal isomers, fragments and, at most, minor amounts of benzene. Fragment composition indicated that pronounced cracking occurs over Pt-HY only, together with minor hydrogenolysis on the metallic centers. This latter reaction is responsible for most fragments over the other three catalysts. Metal-catalyzed C5-cyclic isomerization, ring closure, and pronounced aromatization prevail over Pt-NaY and Pt-NaX. The latter behaves like a typical non-acidic metal catalyst. Pt-NaY exhibits an outstanding aromatization selectivity which can possibly be attributed to the interaction of basic centers of the framework with the Pt particles rather than to geometric reasons.