The title tricyclic diene, C(24)H(22)Cl(2), is the product of thermal ring-opening of a corresponding basketane (penta-cyclo-[4.4.0.0(2,5).0(3,8).0(4,7)]deca-ne) derivative. The cyclo-butene ring is planar to within 0.0032 (12) Å and its geometry is normal. The two 4-chloro-phenyl groups are oriented in an approximately face-to-face conformation with a dihedral angle of 44.14 (6)° between them. The 4-chloro-phenyl group bonded to the cyclo-butene ring lies almost in the plane of the cyclo-butene ring, with a dihedral angle of 8.29 (17)° between the ring planes. The average intra-molecular C⋯C distance between the two C=C bonds is 2.92 Å. In the crystal structure, the mol-ecules are well separated with no close C-H⋯Cl or C-H⋯π inter-molecular inter-actions.