Imidazolin-2-imine and imidazolidin-2-imine ligands are versatile N donors in transition metal chemistry. Here, we describe the synthesis and characterization of (arene)Ru complexes with these ligands. Simple adducts of the type [(p-cymene)Ru(L)Cl-2] (L = 1,3-diarylimidazolin-2-imine or 1,3-dimesitylimidalzolidin-2-imine) can be converted into complexes in which the imines act as pi ligands with tethered imine groups. Furthermore, the high basicity of the N donor group can promote self-activation of the (arene) Ru complexes.