The unit-cell dimensions and space group of the second monoclinic polymorph of the title compound, C15H11FO, differ from those of the previously reported form [Jing (2009 ▶). Acta Cryst. E65, o2515]. The title compound shows an E conformation of the C=C bond with the 4-fluoro-phenyl group opposite to the benzoyl group. The torsion angle of between the planes of the 4-fluoro-phenyl and benzoyl groups is 10.53 (6)°. In the crystal, weak C-H⋯O and C-H⋯F inter-actions form a cross-linked packing motif, building sheets parallel to (-102).