The synthesis of different ruthenium(II) complexes with an [Ru(NHC)4]2+ (NHC = N‐heterocyclic carbene) core is reported. The reaction of [(η6‐C6H4MeiPr)RuCl(μ‐Cl)]2 with 1 equiv. of the NHC iPr2Im in thf leads to the clean formation of [(η6‐C6H4MeiPr)Ru(iPr2Im)Cl2] (1), but use of an excess of the carbene at higher temperatures affords side products such as [Ru(iPr2Im)4H]Cl (9). Complexes of the type [Ru(R2Im)4Cl2] [R = Me (2), nPr (3), MeiPr (6)] were synthesized by the reaction of [Ru(PPh3)3Cl2] with Me2Im, nPr2Im, and MeiPrIm. Compound 6 was isolated as a mixture of isomers that differ in the relative orientation of the asymmetrically substituted NHC ligand with respect to the Ru–Cl vector. Replacement of the chlorido ligands in 2 and 3 with acetonitrile leads to the formation of [Ru(R2Im)4(CH3CN)]Cl2 [R = Me (4), nPr (5)]. At higher temperatures, complex 6 eliminates HCl under C–H activation of one of the NHC ligand iPr groups to give the cyclometallation product 7. The reaction of [Ru(PPh3)3Cl2] with iPr2Im afforded the cyclometallation product [Ru(iPr2Im)3{iPr(C3H6)Im}Cl] (8) or the hydrido complex [Ru(iPr2Im)4(H)]Cl (9) as the main product depending on the reaction conditions. The complexes 1, 3, 4, and 7 as well as two isomers of 6 were structurally characterized.