Exosomes are nanosized vesicles secreted by cells, which are capable of carrying signaling molecules in the forms of protein, mRNA and miRNA to serve as the platforms for complex intercellular communications. During the past few years, increasing efforts have been devoted to exosome research, and tremendous progress has been made in terms of identifying the molecular composition, elucidating the mechanisms and regulations of biogenesis and characterizing the functions in a variety of physiological and pathological settings including cardiovascular diseases, a leading cause of morbidity and mortality in modern society. This review provides an update on exosome research and summarizes the roles of exosomes in cardiovascular diseases.