In the title compound, [Mo(C(27)H(38)N(4)O(2))O(2)], the Mo(VI) atom is coordinated by two oxide O atoms and by two O and two N atoms of the tetra-dentate Schiff base ligand in a distorted octa-hedral geometry. The Mo-N bond trans to a terminal oxide group is significantly longer than the other Mo-N bond, which is attributed to the strong trans effect of the oxide O atom. The dihedral angle formed between the substituted benzene rings is 71.79 (14)°. One of the ethyl groups is disordered over two sets of sites, with a refined site-occupancy ratio of 0.588 (18):0.412 (18).