The interaction of ammonium tetrathiomolybdate with the barium salts of the dithiocarbamates (dtc) of glycine, DL-alanine and DL-2-aminobutyric acid yielded Ba[Mo2S4(dtc)2]. The molar conductivities (∼ 50 Ω-1 cm-1) in DMSO indicated the ionic nature of the complexes. The subnormal magnetic moment (0.4 B.M.), electronic and IR spectral data and CVM peak potentials ( -0.95 and -1.25 V vs SCE) suggested a dimeric species with a [Mo2S4]2+ core. The IR spectral data suggested the bidentate coordination of the dithiocarbamate groups and the absence of coordination by the carboxylate group. Thermal properties of the complexes are discussed. © 1992.