In the crystal structure of the title compound, C(21)H(15)BrNO(2) (+)·CF(3)SO(3) (-), adjacent cations are linked through C-Br⋯π and π-π contacts [centroid-centroid distance = 3.744 (2) Å], and neighbouring cations and anions via C-H⋯O, C-F⋯π and S-O⋯π inter-actions. The acridine and benzene ring systems are oriented at a dihedral angle of 18.7 (1)°. The carb-oxy group is twisted at an angle of 69.3 (1)° relative to the acridine skeleton. The mean planes of adjacent acridine moieties are either parallel or inclined at an angle of 27.8 (1)° in the lattice.