In the title linear coordination polymer, {[Cu(C2H 3O2)2(C12H10N 4)]·2H2O} n , the CuII atom is coordinated by two N atoms from two different symmetry-related 1,4-diimidazol-1-ylbenzene (dib) ligands and two carboxyl-ate O atoms from two acetate ligands in a square-planar geometry. The Cu atoms are linked by the dib ligands, forming an extended chain. These chains are linked by O- H⋯O hydrogen bonds into a three-dimensional supra-molec...