Mesenchymal stem cells (MSCs) can be found in many types of adult tissues such as the bone marrow, adipose, placenta, liver, and periosteum. Recently, adipose tissue-derived MSCs (ADMSCs) have become one the most preferred MSC types because of their fast proliferation rate, abundance, and high plasticity for variable cell types. It is known that ADMSCs are able to differentiate into various cells, including osteoblasts, so they are quite promising for orthopedic clinical trials. The present study aimed to compare the osteogenic differentiation conditions of MSCs from human adipose tissue (hADMSC) and those of MSCs from rat adipose tissue (rADMSC). Therefore, differentiation experiments with five different media and two (human and rat) ADMSC types were performed and the mineralization responses of hADMSCs and rADMSCs were different.