The packing of the title compound, [Na(C(9)H(5)ClNOS(2))(H(2)O)](n), in the crystal structure occurs by pairwise attachment of +sc- and -sc-arranged 4-(4-chloro-phen-yl)-2-thioxo-2,3-dihydro-thia-zol-3-olate subunits via S to sodium. Water mol-ecules that are bound in the axial position of the distorted octa-hedral coordination octahedron give rise to a stereogenic center at sodium.