The octa-hedral cluster core of the anion in the structure of the title compound, (C(16)H(36)N)(3)[Mo(6)(C(4)H(9)S)(6)(μ(3)-Cl)(7)(μ(3)-S)]·2H(2)O, has -3 site symmetry. Two μ(3)-Cl atoms fully occupy positions in the cluster core, while the remaining six positions are statistically occupied by Cl and S atoms in a 1:5 ratio. The fully occupied Cl-atom positions are located on sites with 3 symmetry, and the N atom of tetra-butyl-ammonium cation is located on a site with 2 symmetry. The structure contains also two disordered solvent water mol-ecules, one of which is located on a threefold rotation axis and the other in a general position, both with an occupancy of 0.25. The water mol-ecules are localized in cavities formed by the tetra-butyl-ammonium cations and the tert-butane-thiol-ate groups. The metal clusters are stacked in a cubic close packing arrangement along [001].