The title compound, trans-[RhCl(C(18)H(14)BrP)(2)(CO)], has a slightly disordered square-planar geometry with the Rh ion(I) situated on an inversion the centre and carbon-yl-chloride disorder observed as a result of the crystallographic inversion symmetry. Selected geometric parameters include: Rh-P = 2.3430 (8) Å, Rh-Cl = 2.434 (3) Å, Rh-C = 1.722 (8) Å, P-Rh-P = 180.00 (3)°, P-Rh-Cl = 95.40 (7)°, 84.60 (7)° and Rh-C-O = 177.9 (8)°.