The tris(phenyltin)-substituted tungstoantimonate(III) Cs-6[(PhSn)(3)Na-3(alpha-SbW9O33)(2)]. 20H(2)O (1) and the tetrakis(phenyltin)-substituted tungstoarsenate(III) Nas[{(PhSn)(2)O}(2)H(alpha-AsW9O33)(2)]. 20H(2)O (2) have been prepared by reaction of phenyltin trichloride with Na-9[alpha-SbW9O33]. 19.5H(2)O and Na-9[alpha-AsW9O33]. 19.5H(2)O, respectively, in aqueous solution. The products were characterized by elemental analysis, X-ray crystallography, multinuclear NMR, and infrared spectroscopy. Crystals of 1 are monoclinic, space group P2(1)/n, with a 13.7952(1) Angstrom, b = 22.3133(2) Angstrom, c = 34.4493(2) Angstrom, beta = 90.933(1)degrees, and Z = 4. Anion 1 has nominal D-3h symmetry and contains three PhSn3+ groups and three sodium ions sandwiched between [alpha-SbW9O33](9-) units. Crystals of 2 are triclinic, space group P (1) over bar, with a = 15.272(6) Angstrom, b = 15.303(6) Angstrom, c = 16.760(7) Angstrom, alpha = 93.59(3)degrees, beta = 106.187(19)degrees, gamma = 112.23(3)degrees, and Z = 1. Anion 2 has nominal C-2h symmetry and contains four PhSn3+ groups sandwiched between two [alpha-AsWs(9)O(33)](9-) units.