The complex [SbCl6]3− in CHCl3 shows a phosphorescence (λmax = 520 nm, ø = 2.4 X 10−3, τ 50 ns) originating from the lowest sp excited state. Oxygen quenches this luminescence and participates in the photooxidation of Sb(III): [SbCl6]3− + O2 → [SbCl6]− + O22−. At λirr = 263 nm the quantum yield was ø = 0.081. The photoproduct [SbCl6]− in CHCl3 is light-sensitive too. Ligand to metal charge transfer excitation induces a reduction of Sb(V): [SbCl6]− + 2Cl− → [SbCl6]3− + Cl2. At λirr = 272 nm the quantum yield was ø = 0.1. The photogenerated chlorine undergoes secondary reactions.