New dioxidomolybdenum(VI) complexes with the formula [MoO2L(MeOH)], derived from N'-(5-chloro-2-hydroxy-benzylidene)-2-methylbenzohydrazide (H2L1) and N'-(3,5-dichloro-2-hydroxybenzylidene)-2-methylbenzohydrazide (H2L2) were prepared. Crystal and molecular structures of the complexes were determined by single crystal X-ray dif-fraction method. Both complexes were further characterized by elemental analysis and FT-IR spectra. Single crystal X-ray structural studies indicate that the hydrazones L1 and L2 coordinate to the MoO2 cores through the enolate oxygen, phenolate oxygen and azomethine nitrogen. The Mo atoms in both complexes are in octahedral coordination. Catalytic properties for epoxidation of styrene by the complexes using PhIO and NaOCl as oxidant have been studied.