β-Bi₂Rh was prepared from the elements in the presence of iodine. At room temperature the lattice constants of the triclinic centrosymmetric structure are a = 6.743 (1), b = 7.030 (1), c = 7.067 (1) Å, α = 104.76 (1), β = 100.73 (1), γ = 105.79 (1)°. X-ray investigations on a single crystal revealed that each Rh atom is surrounded by seven Bi atoms in a monocapped trigonal prism. The prisms share common rectangular and trigonal faces to build infinite rows of double prisms, which are finally connected into parallel (100) layers. Twinning along [010] is commonly observed, indicating a pseudomonoclinic C-centered cell.