In the title compound, C(4)H(14)N(2) (+)·2C(9)H(7)O(4) (-)·2H(2)O, the butane-1,4-diaminium cation lies on an inversion center. In the crystal, inter-molecular N-H⋯O and O-H⋯O hydrogen bonds link the components into layers parallel to (100). Addtional stabilization within these layers is provided by weak inter-molecular C-H⋯O hydrogen bonds.