Exosomes are extracellular vesicles with a diameter of 40-100 nm, which can be produced by several cells. As natural nanoscale vesicles, exosomes have the characteristics of low toxicity, low immunogenicity, strong homing ability, as well as the ability to carry several molecules, which make them potential drug delivery vehicles. Mesenchymal stem cells (MSCs) are an ideal source of exosomes because they can secrete and produce a large number of these vesicles. MSC-derived exosomes (MSCs-Exo) have regeneration and tissue repair functions similar to those of MSCs and can prevent the risk of graft versus host disease and infection caused by MSC transplantation. Therefore, MSCs-Exo are expected to become an effective substitute for the biological functions of MSCs. In this review, combined with the progress of preclinical and clinical studies, the potential therapeutic applications of MSCs-Exo in cardiovascular diseases, neurological disorders and malignancies was evaluated and discussed.