**Abstract**

Extracellular vesicles (EVs) are newly identified as cell-to-cell communication mediators that carry and transfer various regulatory molecules. Recent studies have shown that EVs play important roles in normal physiology and pathological conditions of human reproduction. In the female reproductive system, EVs in follicular fluid, oviduct fluid, and uterine luminal fluid are considered as vehicles to regulate follicular development, oocyte maturation and mediate embryo–maternal crosstalk to affect embryo implantation and pregnancy. In the male reproductive system, prostasomes and epididymosomes are involved in regulating sperm maturation, motility, capacitation, acrosome reaction, and fertilization. EVs transmitted cargos also play important roles in reproduction-related pathologies, such as polycystic ovarian syndrome, endometriosis, pregnancy complications, male infertility, and gynecological malignant tumors. In view of the important roles in the reproductive system, EVs may be used as biomarkers or therapeutic targets for reproductive abnormalities and related diseases. In this chapter, we sorted EVs in human reproduction through their physical/pathological functions and mechanisms, and listed several EVs as biomarkers and clinical therapeutic applications in the future.

**Keywords:** extracellular vesicles, exosome, reproductive system, polycystic ovarian syndrome, endometriosis, pregnancy disorders, male infertility
