Presented work focuses on the response of osteogenic, osteoblastic and mesenchymal stem cells to real and simulated microgravity. Mesenchymal stem cells are the residents of adult bone marrow stroma. These cells are capable of differentiating towards osteogenic, adipogenic and chondrogenic lineages. The advantage of using MSCs in space-related research is that these cells are relevant tool to develop bone tissue. Osteogenic potential of MSCs allows investigating osteogenesis from the most uncommitted cells while still maintaining all main characteristics of bone differentiation (osteogenic gene expression, osteogenic markers, matrix maturation and mineralization). Recent studies have demonstrated that MSCs are targeted by microgravity and accordingly can be involved in space flight-induced osteopenia. These findings determine the necessity of further study of human MSC biology in real and simulated microgravity conditions.