Mesenchymal stem cells (MSC) are considered non-hematopoietic multipotent stem cells with self-renewal properties and the ability to differentiate into a variety of mesenchymal tissues. Optimal conditions for the culture of these cells have been the subject of investigation for several years. In particular, ideal oxygen tension levels have not been established in the literature. In physiological environments, oxygen tension may vary from 12% in peripheral blood to 1% in the deep zone of cartilage regions. In any case, oxygen tension is considerably lower in vivo when compared with the normal atmosphere of standard cell culture conditions (21%). The objective of this study was to review the literature available on MSC characteristics (cell cycle, survival, proliferation, differentiation, morphology, immunophenotype, cytogenetics) when cultured under hypoxic conditions. Our focus on optimal culture conditions is justified by the key role currently played by these cells in regenerative medicine.