Bisgermavinylidene [(Me3SiN═PPh2)2C═Ge→Ge═C(PPh2═NSiMe3)2] (1) has been used as a source of unstable germavinylidene for the synthesis of a series of heterobinuclear complexes. The reaction of 1 with stoichiometric amounts of transition metal chlorides MCl2 (M = Mn, Fe) yielded [(Me3SiN═PPh2)2(GeCl)CMn(μ-Cl)]2 (2) and [(Me3SiN═PPh2)2(GeCl)CFeCl] (3), respectively. Treatment of 1 with Me3SiN3 gave the [2 + 3] cycloaddition product [(Me3SiN═PPh2)2CGeN(SiMe3)N═N] (4). While similar reaction of 1 with ((n)Bu)3SnN3 ((n)Bu = n-butyl) and water-borane adduct H2O → B(C6F5)3 afforded the 1,2-addition products [(Me3SiN═PPh2){((n)Bu)3Sn}CPPh2NSiMe3GeN3] (5) and [HC(PPh2═NSiMe3)2Ge(OH)B(C6F5)3] (6), respectively. The results suggested that the germanium-carbon bond in germavinylidene is capable of forming addition reaction products. The X-ray structures of 2-6 have been determined.