In the crystal structure of the title dinuclear compound, [Ni(2)(C(4)H(4)O(5))(C(16)H(36)N(4))(2)](ClO(4))(2)·H(2)O, the bridg-ing di-car-box-yl-ate dianion O,O'-chelates to two Ni atoms, both of which are also chelated by the N-macrocylic ligand. The Ni atoms exhibit a distorted octa-hedral coordination. N-H⋯O and O-H⋯O hydrogen bonds link the cations and the uncoordinated water mol-ecules into a layer structure; the perchlorate anions occupy the space between adjacent layers, and are only weakly linked to the layers. One of the perchlorate anions is disordered over two sets of sites in a 3:2 ratio.