A new functionalized cluster, [Ge5Ni2(CO)3]2-, derived from the closo-[E5]2- (E = Si-Pb) anions which have been known for decades but whose reactivity has rarely been studied, was successfully isolated from the reaction of [Ni(PPh3)2(CO)2] and [Ge5]2- in ethylenediamine (en) solution, and its formation pathway was also investigated.