Abstract The role of solvent in the alkali-catalyzed hydrolysis of organosilicon hydrides, specifically, 3-[(2-methoxy) ethoxy] propyldimethylsilane, has been investigated kinetically in dioxane/water media by varying the solvent composition. Statistical analysis of the kinetic data indicates that approximately three water molecules are involved in the transition state of the rate-determining step. The mechanistic implications are discussed.