The hydrogenation of(-)-menthone, (+)-isomenthone, and (+)-pulegone over SiO2-supported Pt and Pt-Sn catalysts was studied in this work. The modification with tin was performed by means of the techniques of surface orgarrometallic chemistry on metals. This way of modifying the catalysts allowed stereoisomers of menthol to be obtained in a one-step process. The hydrogenation of these terpenones was favored by the presence of tin in the bimetallic phase.