Mesenchymal stem cells (MSCs) have tremendous potential for regenerative medicine, and have been researched for the treatment of cardiovascular diseases. MSCs are a promising cell type because of their ease of isolation and expansion, their multipotency and their low immunogenicity. However, in order to fully utilize the therapeutic potential of MSCs, it is important to understand the intrinsic property of MSCs and the role of the microenvironment in modulating MSC behavior and function. Microenvironmental factors such as mechanical cues, soluble factors and matrix properties not only regulate MSC differentiation, but also modulate MSC signaling to the surrounding environment. Understanding the properties of MSCs and the role of the microenvironment will be beneficial for developing in vivo therapies for the construction of tissue-engineered vascular grafts and the treatment of ischemic cardiac tissues.