ENTPDs, a group of enzymes involved in the hydrolysis of phosphate bonds within purine and pyrimidine metabolic pathways, extend their influence beyond metabolism to modulate the immune landscape within the tumor microenvironment (TME). Among these enzymes, eight distinct subtypes, namely ENTPD1–8, have been identified. While these enzymes are predominantly present on the cell surface, they can also be located within intracellular organelles. Substrate preferences vary among the various ENTPD subtypes. While cancer research has largely focused on immune and tumor-related aspects, the metabolic aspects of ENTPDs have received relatively little attention. This chapter provides an informative overview of how ENTPDs participate in shaping the TME and influencing cancer progression, shedding light on their potential as critical components in future cancer therapy strategies.