Two polynuclear copper(II) complexes with hydroxido-bridging ligands and polycyanide units, [Cu{Cu(tn)}6(μ2-OH)2(μ3-OH)4Cl2](tcm)4Cl2·2H2O (1) and [{Cu(bpy)}4(OH)4(dca)2](dca)2·bpy·2H2O (2) (tn = NH2(CH2)3NH2; tcm− = [C(CN)3]−, bpy = 2,2′-bipyridyl, dca− = [N(CN)2]−) have been prepared by one-pot reactions. The structure of 1 consists of a centrosymmetric heptanuclear ion [Cu{Cu(tn)}6(μ2-OH)2(μ3-OH)4Cl2]6+. The tcm− and the halide anions which appear as counter-ions in the formula unit, play an important role in the stabilization of the complex since the hydrogen bonding between nitrogen atoms of the tcm− anion and halide anions, and hydrogen atoms of the terminal water molecule and of the bridging hydroxido ligands generate an overall three-dimensional structure. The crystal structure of 2 is essentially built on discrete centrosymmetric tetranuclear [{Cu(bpy)}4(μ2-OH)2(μ3-OH)2(dca)2]2+ units including two μ2- and two μ3-OH ligands. As observed for 1, the dca− anions form a network of hydrogen bonding between their nitrogen atoms and hydrogen atoms of water molecules generating a two-dimensional structure. The magnetic susceptibility data indicate antiferromagnetic interactions in 1 and ferromagnetic ones in 2.