Three optically active Molybdenum (VI) dioxo complexes with tetrahydro salen and substituted tetrahydro salen derivatives as ligands were synthesized and examined as catalysts for asymmetric epoxidation. Complexes of the type MoO2(L)(Solv) and WO2(L) (L=tridentate, trans-2-aminocyclohexanol derived chiral Schiff base, Solv=alcohol) were prepared and characterized by elemental analysis, NMR and IR spectroscopy. These complexes are applicable as catalysts for olefin epoxidation reactions with tert-butyl hydroperoxide (TBHP) being the oxidizing agent. In case of cis-β-methylstyrene moderate enantiomeric excesses of up to 26% can be reached when the reaction is carried out at 0℃.