The asymmetric unit of the title compound, [Zn(5)(C(12)H(12)O(4))(4)(OH)(2)(C(10)H(8)N(2))](n), consists of three Zn(II) ions (one of which is located on a twofold rotation axis), two 5-tert-butyl-isophthalate ligands, one 4,4'-bipyridine ligand and one hydroxide group. The five Zn(II) ions form a penta-nuclear zinc cluster, which is further bridged by ten organic ligands, forming two-dimensional sheets. The central zinc ion of the cluster has site symmetry 2 and is octahedrally coordinated in a N(2)O(4) donor set, whereas the other four zinc atoms are tetrahedrally coordinated by four O atoms. The coordination modes for the 5-tert-butyl-isophthalates are bis-(bidentate) or bidentate-monodentate. Hydrogen bonds are formed between adjacent sheets through the hydroxide groups and the O atoms of the monodentate carboxyl-ate groups. The two tert-butyl groups are disordered over two positions with ratios of 0.64 (2):0.36 (2) and 0.85 (3):0.15 (3).