Melting reactions of Bi with Pt and BiCl₃ yield shiny black, air insensitive crystals of the subchlorides Bi₆[PtBi₆Cl ₁₂] and Bi_2/3[PtBi₆Cl¹²]. Despite the substantial difference in the bismuth content the two compounds have almost the same pseudo-cubic unit cell and follow the structural principle of a CsCl type cluster salt. Bi⁶[PtBi₆Cl₁₂] consists of cuboctahedral [PtBi⁶Cl₁₂]^2- clusters and Bi₆²⁺ polycations (a = 9.052(2) Å, α = 89.88(2)°, space group P1, multiple twins). In the electron precise cluster anion, the Pt atom (18 electron count) centers an octahedron of Bi atoms whose edges are bridged by chlorine atoms. The Bi₆²⁺ cation, a nido cluster with 16 skeletal electrons, has the shape of a distorted octahedron with an opened edge. In Bi_2/3[PtBi₆Cl¹²] the anion charge is compensated by weakly coordinating Bi³⁺ cations which are distributed statistically over two crystallographic positions (a = 9.048(2) Å, α = 90.44(3)°, space group R3̄). Bi ₆[PtBi₆Cl₁₂] is a semiconductor with a band gap of about 0.1 eV. The compound is diamagnetic at room temperature though a small paramagnetic contribution appears towards lower temperature.