In the cation of the title salt, C(12)H(14)N(3)O(+)·C(24)H(20)B(-), the dihedral angle between the quinoline ring and the mean plane of the urea fragment is 61.51 (5)°. In the crystal, the cations inter-act through weak C-H⋯O hydrogen bonding, forming a zigzag chain along the c-axis direction; the cations and anions are involved in weak inter-molecular C-H⋯π and N-H⋯π inter-actions as donors and acceptors, respectively.