Öz In the present work, new Schiff-base derivative of (E)-2-bromo-4-chloro-6-[(4-chloro-2,5-dimethoxyphenylimino)methyl]phenol, formula sum is given by C15H12BrCl2NO3 (I), has been synthesized and characterized by single-crystal X-ray diffraction and density functional theory (DFT) molecular orbital calculations. The title compound displays O-H…N intramolecular, weak C-H…O, C-H…Cl intermolecular and a weak π-π stacking interactions which influence crystal packing. The experimental results were compared to the theoretical ones, obtained at DFT level. Theoretical electronic structure calculations of the B3LYP/6-311G(d,p) level were performed optimize the molecular geometry. The values of the total dipol moment (μ), linear polarizability (α) and the first hyper polarizability (β) of the investigated compound were computed using B3LYP/6-311G(d,p) calculations. The energetic behaviors of (I) in different solvents were examined using by time-dependent DFT method by applying the polarizable continuum model. Mulliken population analysis, frontier molecular orbitals, molecular electrostatic potential and thermodynamic properties were also calculated.