Osteoporosis and periodontitis affect a large number of men and women worldwide with increase in incidence with advancing age. Periodontitis has long been defined as an infection mediated destruction of the alveolar bone and soft tissue attachment of the tooth, responsible for tooth loss among adult populations. Several studies support an association of osteoporosis with the onset and progression of periodontal disease in humans. Systemic loss of bone density in osteoporosis including that of the oral cavity may provide a host system that is increasingly susceptible to infectious destruction of periodontal tissue. Understanding the association between these common diseases and the mechanisms underlying these associations will aid health professionals to provide improved means to prevent, diagnose and treat these very common diseases.