Extracellular vesicles (EVs), including exosomes derived from stem cells, hold significant potential for disease treatment due to their role in cellular communication via the proteins, lipids, and nucleic acids they convey. However, their application in clinical practice faces challenges due to substantial variability in their composition, sensitivity to production conditions, and contamination risks. This chapter emphasizes the importance of quality control for EV products to ensure their safety and efficacy in clinical use. Key quality control parameters include safety assessments (such as detection of microbial contamination, endotoxins, mycoplasma, and residual bovine serum albumin), as well as evaluations of purity and biological activity (through in vitro assays of cell proliferation, migration, angiogenesis, and immune modulation). The chapter highlights the necessity of integrating standardized manufacturing processes with robust analytical techniques to address the challenges of EV heterogeneity and contamination. By adhering to global regulatory frameworks, these strategies aim to ensure that EV-based therapies are both safe and effective, facilitating their clinical deployment.