Cs-Pt/MCM-41 catalysts with basic character have been prepared by selective adsorption of Pt(NH3)(4)(OH)(2) at pH = 8 on pure silica MCM-41 followed by incipient-wetness impregnation of CsNO3, then oxidation and reduction. The influence of the amount of Cs (0, 2 and 4 wt%) on the size of the reduced Pt particles and on their catalytic behavior in the conversion of n-hexane has been investigated. Whatever the Pt content (0.7 or 2.0 wt% Pt) the selectivity to benzene reaches values close to those obtained on Cs-renriched Pt/Cs-BEA zeolite. However, the catalytic stability is lower. The catalytic trends are discussed in view of the physicochemical properties of the solids determined by chemical analysis, N-2 physisorption, XRD and TEM before and after catalytic test.