The heterometallic coordination compound [Cu(Lys)(phen)]2V4O12·4H2O (Lys is the amino acid lysine, C6H14N2O2, and phen is 1,10-phenanthroline, C12H8N2) lies across an inversion centre. Two [Cu(Lys)(phen)]2+ units coordinate to the cyclo-vanadate fragment and the formula unit is completed by four solvent water molecules. The lysine ligand is in the zwitterionic form and chelates the CuII atom via the α-NH2 and α-COO− donor groups, while the ∊-NH3 + group is involved in intramolecular hydrogen bonds with the central [V4O12]4− core and with solvent water molecules. In the crystal, N—H...O and O—H...O hydrogen bonds connect the components of the structure to form a three-dimensional network. The crystal structure is further stabilized by π–π interactions involving the phen ligands. The lysine group is disordered over two sets of sites with refined occupancies of 0.534 (11) and 0.466 (11).