In the title compound, {[Na(C(4)H(7)O(3))(H(2)O)(2)]·H(2)O}(n), the sodium ion is octa-hedrally coordinated by two bridging 1,4-anhydro-erythritolate ligands, unexpectedly coordinated by the ring oxygen and four water ligands. This bonding pattern leads to one-dimensional anti-tactical polymeric chains along [010]. One of the exocyclic O atoms of the anhydro-erythritolate group is an acceptor in four hydrogen bonds, giving further evidence that it is deprotonated.