"Osteobiologics" is the term that has been introduced to refer to the class of engineered materials that have been created and which promote healing of fractures and bone defects. The list of osteobiologics is rapidly expanding as new products incorporating osteoconductive materials are mixed with a variety of osteoinductive proteins, demineralized bone, and preparations of osteogenic cells. The growth in osteobiologics has been stimulated by the early success of osteoconductive materials as graft substitutes in the repair of fractures and by the increasing demand for grafts in all areas of orthopaedics. Although allografts have historically been employed with success, the number of donors has grown much slower than demand leading to the development of artificial materials. Manufactured bone graft substitutes, or osteobiologics, attempt to mimic the components of an autogeneous bone graft by reproducing the bone matrix, which is osteoconductive and osteoinductive. Other products aim to introduce osteogenic cells by concentrating bone marrow while others introduce differing growth factors from platelets in peripheral blood. Very few of these products have been supported by appropriate clinical studies and as such their value is unknown. Orthopaedic surgeons employing these products must understand the basic science principles behind their development in order to understand the indications and limitations of their application. Properly designed clinical studies should be performed to determine the usefulness and cost-effectiveness of both current and future products.