The Au(I) atom in the title compound, [Au(C(21)H(24)N(2))(2)](C(24)H(20)B(5)O(6)), adopts a slightly distorted linear AuC(2) coordination geometry arising from its coordination by two mesitylenic N-heterocyclic carbene ligands, forming an overall cationic complex. The dihedral angle between the imidazole rings is 57.3 (6)°. In the crystal, the components are linked by weak C-H⋯O hydrogen bonds.