In a new polymorphic form of dichloridotriphenylantimony, [Sb(C6H5)(3)Cl-2], there are two crystallographically unique molecules in the asymmetric unit and it has been determined that this polymorph is one of two kinetically favoured phases of pure dichloridotriphenylantimony, both of which have Z' > 1. A third polymorph, corresponding to (C6H5)(3)SbCl1.8F0.2, is also known and has Z' = 2. By contrast, the thermodynamically preferred polymorph of pure (C6H5)(3)SbCl2 has Z' = 1. A brief comparison of the known polymorphic forms of dichloridotriphenylantimony is presented.