The title compound, C(27)H(39)N(2) (+)·C(24)H(20)B(-)·2CH(2)Cl(2), is the first reported imidazolidinium cation with the sterically demanding 2,6-diisopropyl-phenyl groups in the 1,3-positions. The crystal structure is stabilized by weak inter-molecular C-H⋯π(arene) inter-actions. Due to the bulky nature of both the flanking 2,6-diisopropyl-phenyl substituents and the tetra-phenyl-borate counter-ion, anion inter-actions with the imidazolidinium H atom in the 2-position are not observed, also a first for this class of ortho-alkyl-substituted Arduengo-type carbene precursors.