The oxo-thio-W(VI) complexes Tp*WOS(S2PR2-S) and Tp*WOS(pyS-S) (Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate, R = OEt, Ph; pyS = pyridine-2-thiolate) have been prepared and characterized by microanalytical, spectroscopic, and structural techniques. Crystals of the 1,2-dichloroethane hemisolvate of Tp*WOS(S2PPh2-S) belong to the triclinic space group P (1) over bar with a = 10.732(6) Angstrom, b = 16.91(1) Angstrom, c = 10.021(4) Angstrom, alpha = 104.40(4)degrees, beta = 107.52(3)degrees, gamma = 96.09(5)degrees, V = 1647(1) Angstrom(3) for Z = 2. The complex exhibits a distorted octahedral structure featuring a facial tridentate Tp* ligand and mutually cis terminal oxo (W-O(1) = 1.712(7) Angstrom), terminal thio (W-S(1) = 2.162(3) Angstrom), and monodentate dithiophosphinate ligands. X-ray absorption and extended X-ray absorption fine structure results support a related oxo-thio formulation for Tp*WOS(pyS-S). The complexes are reduced to the corresponding oxo-thio-W(V) anions, [Tp*WOS(S2PR2-S)](-) and [Tp*WOS(pyS-S)](-), which exhibit highly anisotropic EPR spectra. They are oxidized to form the EPR-active (dithio)oxo-W(V) cations, [Tp*WO(S3PR2-S,S')](+) and [Tp*WO(pyS(2)-N,S)](+) (pyS(2) = pyridine-2-dithio). Green [Tp*WO(pyS(2)-N,S)]BF4, formed in the reaction of Tp*WOS(pyS) and NOBF4, has been isolated and spectroscopically and structurally characterized. Crystals of [Tp*WO(pyS(2)-N,S)]BF4 belong to the monoclinic space group Cc with a = 16.007(5) Angstrom, b = 14.091(4) Angstrom, c = 13.608(4) Angstrom, beta = 124.525(4)degrees, V = 2528.8(13) Angstrom(3) for Z = 4. The cation exhibits a distorted octahedral structure featuring facial tridentate Tp*, terminal oxo (W-O(1) = 1.632(12) Angstrom), and bidentate pyridine-2-dithio-N,S (W-S(1) = 2.317(7) Angstrom, S(1)-S(2) = 2.037(9) Angstrom) ligands. The structures and redox behavior of the complexes are compared and contrasted with those of the related molybdenum complexes, Tp*(MoOS)-O-VI(S2PR2-S) and Tp*(MoO)-O-IV(pyS(2)-N,S).