The new lithium guanidinate salt [Li{μ-κ1,κ2,N,N′-(NEt)(N-t-Bu)CNMe2}(THF)]2 (1) was obtained by the reaction of HNMe2 with n-BuLi and further reaction with the asymmetric carbodiimide EtN=C=N-t-Bu. Guanidinate-supported zirconium complexes [Zr{κ2,N,N′-(NEt)(N-t-Bu)CNMe2}(μ-Cl)Cl2]2 (2), [Zr{κ2,N,N′-(NEt)(N-t-Bu)CNMe2}3Cl] (4), [Zr{κ2,N,N′-(NEt)(N-t-Bu)CNMe2}2(η5-C5H5)Cl] (5) and [Zr{κ2,N,N′-(NEt)(N-t-Bu)CNMe2}(η5-C5H5)2Cl] (6) were prepared. Complexes 2, 4, and 6 were synthesized by the metathesis reaction of ZrCl4 or [ZrCl2(η5-C5H5)2] with 1. The previously described complex [Zr{κ2,N,N′-(NEt)(N-t-Bu)CNMe2}2Cl2] (3), which was prepared by the insertion reaction of EtN=C=N-t-Bu into a metal–amido bond of [Zr(NMe2)2Cl2(THF)2], allowed the new complex 5 to be obtained by reaction with NaC5H5. All of the new complexes were characterized spectroscopically and the molecular structures of 1, 4, and 6 were determined by single-crystal X-ray diffraction.