Of the great classes of nanocluster crystallization, "cocrystallization" has gained significant attention due to its elucidation of both intracluster structures and intercluster packing modes. In addition, the intermolecular interactions and resulting assembled constructs endow the cocrystallized materials with novel physical and chemical properties that differ from those of the individual components. Heterogeneous cocrystallization has recently emerged as a new "growth point" in nanocluster science. In this Perspective, we elaborate on relevant advances in studying the cocrystallization of metal nanoclusters. The packing patterns of the cocrystallized nanoclusters, as well as their geometric structures, are discussed case by case. In addition, the intercluster interactions among heterogeneous nanoclusters that account for the cocrystallization are also disclosed. The goal of this Perspective is to provide researchers attempting to study nanocluster cocrystallization with research fundamentals and to further propose some possible approaches (or new growth points) for the design and fabrication of cocrystallized cluster systems.