An important clinical problem is the fast restoration of large bone defects caused by trauma, tumour resection, infections, or skeletal anomaly. Autografts and allografts are commonly known approaches to bone repair, however, they have a lot of limitations. Bone tissue engineering has been considered as the alternative solution to bone rebuilding when natural grafts cannot be used. The primary model of bone tissue engineering comprises three elements: scaffold, growth factors, and stem or progenitor cells. The role of cells is to differentiate into osteoblasts and to form a bone extracellular matrix. Mesenchymal stem cells (MSCs) possess the mentioned features which make them a promising tool in supporting bone restoration process. MSCs are present in multiple tissues, including bone marrow and adipose tissue. This study presents the similarities and differences between bone marrow-derived mesenchymal stem cells (BMDSCs) and adipose tissue-derived mesenchymal stem cells (ADSCs). The study also compares the osteogenic potential of these cells, based on available literature. The presented comparison showed that both BMDSCs and ADSCs possess osteogenic ability under in vitro and in vivo conditions. However, most of the in vitro research confirmed the inferior osteogenic potential of ADSCs, compared to BMDSCs. Contrariwise, the in vivo studies revealed more controversies on this point in the scientific community; namely, some research studies considered the ADSCs as the promising alternative for BMDSCs which have been successfully used to-date for bone tissue engineering applications