The 4-carboxy-imidazole-5-carboxyl-ate(2-) dianion in the title compound, [Ni(C(5)H(2)N(2)O(4))(C(16)H(36)N(4))]·H(2)O, N,O'-chelates to the Ni(II) atom, which shows an octa-hedral coordination. The macrocycle folds itself around the metal atom and binds to it through four secondary nitrogen atoms; adjacent molecules are linked by N-H⋯O hydrogen bonds into a linear chain. The water molecule is disordered over two positions.