Novel cis-dioxomolybdenum(VI) complexes containing chiral ligands have been prepared and fully characterized, including structural determinations by X-ray diffraction. The first monometallic dioxomolybdenum(VI) complex containing a chiral N,N',O-tridentated ligand is reported. The new complexes were evaluated as catalysts for epoxidation of olefins using tert-butyl hydroperoxide and H2O2 as oxidants. They were found to be efficient catalysts affording good chemoselectivity but low enantioselectivity.