In the title compound, (C(3)H(12)N(2))[Cu(C(7)H(3)NO(4))(2)]·4H(2)O, the Cu(II) atom is six-coordinated in a distorted octa-hedral geometry by two tridentate pyridine-2,6-dicarboxyl-ate (pydc) ligands. In the crystal, inter-molecular O-H⋯O, N-H⋯O and weak C-H⋯O hydrogen bonds, as well as π-π stacking inter-actions between the pyridine rings of the pydc ligands [centroid-centroid distance = 3.4714 (14) Å] are present. C=O⋯π inter-actions between the carbonyl groups and pyridine rings [O⋯centroid distances = 3.150 (2) and 3.2233 (19) Å] are also observed.