In the title salt, C(26)H(29)N(2) (+)·Br(-), which may serve as a precursor for N-heterocyclic carbenes, the imidazolidine ring adopts a twist conformation with a pseudo-twofold axis passing through the N-C-N carbon and the opposite C-C bond. The N-C-N bond angle [113.0 (4)°] and C-N bond lengths [1.313 (6) and 1.305 (6) Å] confirm the existence of strong resonance in this part of the mol-ecule. In the crystal, a C-H⋯Br inter-action is present. The dihedral angle between the biphenyl rings is 64.3 (2)° and the phenyl rings make angles of 76.6 (3) and 18.5 (3)° with the plane of the imidazolidine ring.