In the title compound, {[Nd3(C7H3NO4)3(OH)3]·H2O}n, the NdIII atom is eight-coordinated by the three O atoms of three asymmetrically μ3-bridging hydroxide groups, by four carboxylate O atoms of four different pyridine-2,5-dicarboxylate (2,5-pydc) ligands, and by the N atom of a 2,5-pydc ligand. Six Nd atoms are connected by six hydroxide groups, forming an [Nd6(μ3-OH)6] cluster unit of symmetry -3 and a slightly compressed octahedral geometry. Adjacent [Nd6(μ3-OH)6] clusters are connected by the 2,5-pydc ligands, via O and N atoms, forming chains along the c axis. The remaining O atoms of the 2,5-pydc ligands link these chains into a three-dimensional framework. A disordered water molecule, located on a threefold rotation axis at the opposite side of the [Nd6(μ3-OH)6] cluster and exposed to each of the three Nd atoms, completes the structure.