The title compound, [Cu(C(12)H(8)N(2))(C(18)H(15)P)(2)](2)[Mo(6)O(19)], was obtained by co-crystallization of the mixed-ligand copper complex cation (1,10-phenanthroline)bis-(triphenyl-phos-phane)copper(I), [Cu(phen)(PPh(3))(2)](+), with the Lindquist polyanion [Mo(6)O(19)](2-). The asymmetric unit consists of half a Lindquist anion and one [Cu(phen)(PPh(3))(2)](+) cationic complex. In the cation, there are intra-molecular π-π inter-actions [centroid-centroid distances = 3.617 (2) and 3.7272 (18) Å]. This inorganic-organic adduct is connected by C-H⋯O hydrogen bonds, forming a two dimensional network lying in the ab plane. These networks are connected by C-H⋯π inter-actions into a three-dimensional structure.