The title compound, C(18)H(21)N(3)O(3), is a potential bidentate Schiff base ligand. The whole mol-ecule is disordered with a refined site-occupancy ratio of 0.567 (4):0.433 (4) and not just one ethyl group as reported previously [Sarojini et al. (2007 ▶). Acta Cryst. E63, o4782-o4782]. Using the whole mol-ecule disorder, R values are much smaller than those published. An intra-molecular O-H⋯N hydrogen bond generates a six-membered ring, producing an S(6) ring motif. The dihedral angle between the mean plane of the two benzene rings (major component) is 9.0 (5)°. The crystal structure shows short C⋯C [3.189 (15)-3.298 (12) Å] and C⋯O [2.983 (5)-3.149 (13) Å] contacts. Inter-molecular C-H⋯O inter-actions link neighbouring mol-ecules into dimers with R(2) (2)(18) motifs. In the crystal structure, these dimers are linked together by inter-molecular C-H⋯O inter-actions into one-dimensional extended chains along the b axis. The crystal structure is further stabilized by inter-molecular π-π stacking inter-actions [centroid-centroid distances = 3.458 (8)-3.691 (6) Å].