Paget's disease of bone is a condition of unknown etiology characterized by excessive and abnormalbone remodelling. It may be localized to one or several skeletal segments. The basic symptom of the disease is bone pain, while complications depend on skeletal sites involved and range from secondary osteoarthritis to malignant degeneration. Diagnosis is based usually upon clinical features, imaging, and laboratory analysis. Therapeutic approach is currently based on second generation bisphosphonates. Their use is recommended when bone alkaline phosphatase is high and/or when the disease localizations are highly suspected for determining complications.