\"Bisphosphonates and Osteonecrosis of the Jaw\" stems from a conference held at the New York Academy of Sciences organized by John P. Bilezikian and John T. Grbic (Columbia University College of Physicians and Surgeons, New York, New York), G. David Roodman (University of Pittsburgh Hillman Cancer Center, Pittsburgh, Pennsylvania), and Catherine H. Van Poznak (University of Michigan, Ann Arbor, Michigan). Bisphosphonates work by inhibiting osteoclast action. Millions of people with osteoporosis and other bone diseases have been treated with bisphosphonates. These drugs are also used in chemotherapy to prevent bone pain and bone loss in advanced cancer that has metastasized. In the past few years there have been reports that patients on bisphosphonates have been developing a condition termed osteonecrosis of the jaw (ONJ). The papers in this volume discuss various aspects of ONJ and strategies to move the research on bisphosphonates and ONJ forward, as well as evaluate the risk of ONJ relative to the beneficial effects of bisphosphonates.