The major Raman scattering peaks of BEDT-TTF(CLO(4))(2)have been assigned by comparison to the isotopically labeled C-13(4)-BEDT-TTF(C1O(4))(2) and C-13(6)-BEDT-TTF(C1O(4))(2) salts. The upsilon 2, upsilon 3, and upsilon(6) A(g) modes are associated with the C=C vibrations and the Raman shifts are found to decrease with increasing oxidation state of the ET molecules. The upsilon(9) and upsilon(10) A(g) modes are associated with the sulfur (C-S) related vibrations and the Raman shifts are observed to increase with increasing oxidation state of the ET molecules.