In the title compound, [Cu(2)(C(4)H(4)O(4))(C(10)H(8)N(2))(4)]C(4)H(4)O(4)·12H(2)O, C(10)H(8)N(2)), the centrosymmetic dinuclear cations, succinate anions and water mol-ecules are hydrogen bonded into layers parallel to (010). The Cu atom is square-pyramidally coordinated by one atom of the succinato ligand and four N atoms of two 2,2'-bipyridine ligands. The 12 water mol-ecules form a new type of water cluster.