Osteoimmunology refers to an interdisciplinary research field that combines the field of immunology and osteology. It focuses on the potential treatments and mechanisms associated with bone related diseases, such as rheumatoid arthritis, periodontitis and osteoporosis that are caused by or linked with failure of the immune system. Receptor activator of nuclear factor kappaB ligand (RANKL) is the prime regulator of osteoclastogenesis. It is known to be responsible for the increased activation of osteoclasts, such as direct activation of T cells and indirect increase in the expression of RANKL, and consequently promoting osteoclastic activity. Osteoblasts have significance in the maintenance of the hematopoietic stem cell. Furthermore, they are also relevant in the development of lymphocytes, along with immune cell functions in the development of osteoclast and osteoblast. This book elucidates the concepts and innovative models around prospective developments with respect to osteoimmunology. Also included herein is a detailed explanation of the molecular mechanisms and clinical applications of this field. Those with an interest in this field would find this book helpful.