The title compound, P(C10H7)3·0.5CHCl3, was isolated after the unsuccessful reaction of KSeCN and tris-(naphthalen-1-yl)phosphane. The solvent mol-ecule is disordered about an inversion center. The effective cone angle of the phosphine is 203°. In the crystal, weak C-H⋯Cl and C-H⋯π inter-actions are observed.