Tungstate complexes of alditols have been studied in aqueous solution by W-183 and C-13 NMR spectroscopies. The ligands used in this work may chelate a ditungstate group through several different sites having erythro or threo configurations and therefore yield mixtures of complexes. The structural type of each complex was defined by the characteristic pattern of its W-183 NMR spectrum, and the sites of chelation were identified by C-13 NMR spectroscopy. Alditols which possess an asymmetrical site of erythro configuration (D-arabinitol, D-mannitol, D-glucitol) form two isomeric complexes, as this tetradentate site can be occupied in two reversed orientations. Ribitol forms a single complex of the same type. A single additional complex is formed when another tridentate site of chelation of threo configuration is available (D-arabinitol, D-glucitol). Perseitol (D-glycero-D-galacto-heptitol) affords a pair of erythro complexes involving the tetradentate HO-2,3,4,5 galacto site, together with a third complex of a novel "mixed" bis-dinuclear type. For the latter species, four sharp signals in the W-183 NMR spectrum characterized two ditungstate groups bound respectively to an erythro site (delta-74.2 and -81.4) and a threo site (delta-55.4 and -117.6). These sites were assigned from the C-13 NMR spectrum respectively to the HO-4,5,6,7 and the HO-1,2,3 systems, indicating that the ligand was heptadentate.