Paget's disease of bone, an often undiagnosed metabolic bone disease, can lead to dramatic skeletal changes with enlargement and bowing of the affected bones. The etiology of this localized bone disease has not yet been determined. Genetic factors and viral infections may be involved. Recently, the treatment options for Paget's disease have been greatly improved due to the development of potent bisphosphonates. These agents inhibit osteoclastic bone resorption and allow the suppression of the excessive bone turnover in Paget's disease. This leads to a stabilization of affected bones and to symptomatic improvements. Treatment should be initiated early after diagnosis to limit the extent of damage. The article gives an overview of recent perspectives on epidemiology, diagnosis, and treatment of the disease according to the new German guidelines for the diagnosis and therapy of Paget's disease.