【Abstract】 Exosomes have recently been classified as the family members of “bioactive vesicles” that can promote intercellular communication. Exosomes have garnered a huge amount of interest in recent years. Recent studies on Human Immunodeficiency Virus(HIV),Hepatitis C Virus(HCV),Mycobacterium Tuberculosis, and many other pathogens have demonstrated that exosomes released from infected cells harbor and deliver many regulatory factors including pathogenic DNA or RNA and proteins, cellular miRNA and other host functional genetic elements to neighboring cells, modulating cellular responses. Exosomes can either spread or limit an infection, the same as host immune response. This review highlights the role of exosomes in bacterial and viral infections with an emphasis on their potential contribution to pathogenesis.