New ternary rhenium chalcogenides A 4Re 6X 12 with A = Tl, Cu, Na, Cs, and X = Se; A = Tl, Rb and X = S; A 2Re 6X 12 with A = Pb and X = S, Se have been prepared by high temperature and ion exchange techniques in closed systems. X-ray diffraction powder patterns show them to be isostructural with previously reported A 4Re 6X 12 which are characterized by Re 6X 8 cluster units interconnected into a three-dimensional network structure by X and X 2 linkages. Temperature variation of resistivity measured on sintered pellets shows semiconducting behavior in agreement with 24 electrons per cluster filling the bonding valence band which is separated in energy from the empty antibonding conduction band. Variation of the number and size of the A and X ions are correlated with structural stability in these compounds.