Our study examined whether human bone marrow-derived mesenchymal stem cells (MSCs) are able to differentiate, in vitro, in endothelial and epithelial-like cells. Human MSCs were isolated from sternal punction aspirates, by adherence on plastic. MSCs were cultivated at a density of 5x10⁴cells/cm² in fibronectin-coated flasks on DMEM supplemented with 10% FBS. After 14–21 days cells were harvested and replated at a density of 3x10³cells/cm² in the same culture media supplemented with specific growth factors. For differentiation to the endothelial lineage, VEGF was added. To induce epithelial differentiation, MSCs were cultured using EGF, KGF, HGF, and IGF-II. In the first experiment, after 10–12 days of culture, the cells formed small clusters of adherent and elongated cells, finally forming a monolayer. Immunocytochemical analysis revealed the presence of CD31 and CD144 antigens and von Willebrand factor. In the second experiment, after 7–14 days, when the cells acquired a rounded or polygonal shape, two epithelial markers were identified: cytokeratin 19 (by immunocytochemistry) and 18 (by quantitative RT-PCR). Our data demonstrate that human MSCs are able to differentiate into both endothelial and epithelial cells and may serve as source for tissue engineering.