The reaction of Cs-3[Re6Se7BrBr6] with aqueous ammonia afforded the octahedral rhenium ammine cluster complex cation [Re6Se7Br(NH3)(6)](3+). This cation crystallized as the [Re6Se7Br(NH3)(6)][Re6Se7BrBr6] . 12H(2)O compound. The crystal structure of this compound was established. The presence of the NH3 ligands in the coordination environment about the Re atom was confirmed by thermogravimetry, vibrational spectroscopy, and high-resolution mass spectrometry. The resulting compound is the first example of salts composed of the cluster cation and cluster anion possessing the same (Re6Se7Br) cluster core.