In the title mol-ecule, C(22)H(16)N(2)O, the phenyl ring is twisted slightly with respect to the plane of the central pyrazole ring [dihedral angle = 14.8 (2)°]; the central ring is connected to the naphthyl ring through a -CH=CH-C(=O)- fragment, whose C=C double bond has an E configuration. The pyrazole ring and naphthalene ring system are twisted by 46.3 (1)°. Weak inter-molecular C-H⋯O hydrogen bonds link the mol-ecules, forming supra-molecular chains running along the a axis. The crystal studied was a non-merohedral twin with a component ratio of 0.544 (2):0.456 (2).