The reaction of Ni(NO3)2·6H2O with pyridine-2,6-dicarboxylic acid, NaOH and 2-aminopyrimidine in aqueous solution leads to the formation of the title complex, [Ni(C7H3NO4)(C4H5N3)(H2O)2]·H2O. The NiII ion is coordinated by one N and two O atoms of the tridentate chelating pyridine-2,6-dicarboxylate anion, one heterocyclic N atom of the 2-aminopyrimidine ligand, and two water molecules. The resulting geometry for the [NiN2O4] coordination environment can be described as distorted octahedral. One uncoordinated water molecule completes the asymmetric unit. Extensive O—H⋯O and N—H⋯O hydrogen-bonding interactions between the NH2 group of 2-aminopyrimidine, carboxylate groups, and coordinated and uncoordinated water molecules contribute to the formation of a three-dimensional supramolecular structure.