The presentation of Paget's disease varies from a painful or deforming skeletal affliction to an asymptomatic disorder diagnosed on routine biochemical or radiological assessment. When involvement of the peripheral skeleton by Paget's disease is extensive, the clinical diagnosis is usually clear. Affected bones are thickened and deformed and the overlying skin is warm. Bone pain is sometimes severe and malignant change rarely occurs. The new bone formed is structurally abnormal and is consequently liable to deformity and fractures. Serum alkaline phosphatase concentrations and urinary hydroxyproline excretion are raised. Characteristic X-ray changes are seen. Paget's disease should be treated when it causes skeletal pain and tenderness, or when there are neurological symptoms, fractures, marked deformities, or other complications. New therapeutic agents offer both symptomatic relief and some control of the basic disease process. Simple analgesics should be tried before proceeding to the anti-osteoclastic agents, calcitonin, diphosphonates and mithramycin. All are effective in relieving bone pain and improving biochemical indices. The major advantage of the diphosphonates lies in their oral usage and thus, the number of patients who nowadays require calcitonin is small. The majority of patients should be commenced on a course of diphosphonate therapy (EHDP in most instances), but if clinical response is unsatisfactory calcitonin should be tried. Mithramycin should be reserved for special indications e.g. an elderly patient with severe disabling pain.