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 addition of Cs results in a higher Pt dispersion, a higher initial activity and a higher selectivity for aromatization. On the more basic Pt-richest MCM-41 sample (4 wt% Cs, 2 wt% Pt) the selectivity to benzene reaches values close to those obtained on Cs-enriched 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, N2 physisorption, XRD and TEM before and after catalytic test.