In the title compound, C24H17Cl2N3O3, the quinazolinone ring system is close to planar (r.m.s. deviation = 0.0132 Å), with the imide unit almost perpendicular to it, subtending a dihedral angle of 89.1 (1)°. However, the imide unit itself is not planar, the dihedral angle between the two O=C-N components being 34.6 (1)°. The dihedral angle between the two chlorobenzene rings is 40.50 (7)°, while the angles between these rings and the imide moiety are 54.6 (1) and 58.2 (1)°, respectively. The dihedral angles between the 2-chloro-phenyl rings and the quinazolinone ring system are 48.77 (5) and 32.92 (7)° for rings A and B, respectively. In the crystal, weak C-H⋯O inter-actions link the mol-ecules into a three-dimensional array.