The title complex, [Tb(2)(C(6)H(4)NO(2))(6)(H(2)O)(4)](n), was isolated under hydro-thermal conditions using the ligand pyridine-4-carb-oxy-lic acid (HL) and Tb(2)O(3). The deprotonated L(2-) ligands adopt bridging coordination modes. The central Tb(III) atom is bridged by L(2-) ligands, forming a polymeric chain parallel to the a axis. Supra-molecular O-H⋯N inter-actions link the chains, building up a layer parallel to (010). O-H⋯O hydrogen bonds also occur. Two of the pyridine rings are disordered by rotation around the central C-N direction with occupancy ratios of 0.53 (1):0.47 (1).