Abstract: MFI zeolites based on silicon oxide and, optionally, the oxides of titanium, germanium, zirconium and/or tin, are produced by (1) heating an aqueous, homogeneous reaction mixture which comprises (a) an M.sub.2/n SiF.sub.6 complex (I), wherein M is a cation of valency n, optionally, at least one M.sub.2/n T'F.sub.6 complex (II), wherein T' is titanium, zirconium, germanium and/or tin, (b) a reagent providing OH. ions by hydrothermal decomposition and a structuring agent (c), e.g., a tertiary amine or a quaternary ammonium compound, whereby a zeolite precipitate is formed therein, and (2) separating and calcining such precipitate to eliminate structuring agent from the pores and channels of the resulting zeolite.