In the title compound, C(12)H(9)N(2) (+)·Br(-), the protonated tricyclic ring system is slightly twisted, with a dihedral angle of 3.9 (1)° between the two outer benzene rings. In the crystal, N-H⋯Br and C-H⋯Br hydrogen bonds link two cations and two bromide anions into centrosymmetric assemblies, which are further packed into stacks along [010] via π-π inter-actions between the aromatic rings [centroid-centroid distance = 3.725 (4) Å].