Tumors can reprogram their metabolism through a series of complex biological processes, allowing them to create an environment permissive to their growth and survival. In particular, tumors regulate the metabolism of immune cells within the tumor microenvironment (TME), impairing their antitumor functions to benefit the survival of tumor cells. This chapter will delve deeper into this phenomenon through a detailed summary of the intricate interactions between tumor cells and immune cells. We seek to describe how their metabolic reprogramming influences their interactions and alters the TME dynamics. Furthermore, we will describe novel therapeutic strategies for targeting the metabolism of immune cells to reactivate their antitumor activity. This could potentially open new avenues for more efficacious therapeutic interventions that improve cancer prognosis and patient survival.