The synthesis, crystal structure and physical properties of the new series al and cc:! of radical salts made with bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF or ET) and Keggin polyoxoanions are reported. The structure of the alpha(1)-ET(8)[XW(12)O(40)] (X = Co-II, Cu-II, 2(H+) and Fe-III) series (crystal data : alpha(1)-ET(8)[CoW12O40]. 5.5H(2)O (I), monoclinic, space group I2/m, a = 13.971(9) Angstrom, b = 43.117(7) Angstrom, c = 14.042(5) Angstrom, beta = 107.25(3)degrees, V= 8078 Angstrom(3), Z = 2; alpha(1)-ET(8)[FeW12O40]. 9H(2)O (II), monoclinic, space group 12/m, a = 13.955(10) Angstrom, b = 43.221(7) Angstrom, c = 14.049(3) Angstrom, beta = 107.24(4)degrees, V = 8093 Angstrom(3), Z = 2) consists of alternating layers of the organic donor and the Keggin polyoxometalates. The organic layers contain three crystallographically independent molecules that form two different parallel stacks alternating in the [10 $$($) over bar 1] direction. The structure of the alpha(2)-ET(8)[XW(12)O(40)] (X = Co-II, Cu-II, 2(H+), Fe-III and B-III) series (crystal data : alpha(2)-ET(8)[CoW12O40]. 0.5CH(3)CN . 3H(2)O (III), monoclinic, space group 12/m, a = 16.66(2) Angstrom, b = 43.42(2) Angstrom, c = 12.14(1) Angstrom, beta = 111.78(9)degrees, V = 8151 Angstrom(3), Z = 2; alpha(2)-ET(8)[BW12O40]. 2H(2)O (IV), monoclinic, space group 12/m, a = 16.50(1) Angstrom, b = 43.27(2) Angstrom, c = 12.125(3) Angstrom, beta = 111.99(4)degrees, V = 8026 Angstrom(3), Z = 2) is similar to that of the alpha(1) phase but the organic layers contain only two crystallographically independent molecules.