A 76-year-old woman presented with a 2-month history of high serum calcium, low phosphate, and high levels of alkaline phosphatase. Serum parathyroid hormone, in repeated measurements, was inappropriately high for the high serum calcium levels and the patient had hypercalciuria. The diagnosis of primary hyperparathyroidism was made. The patient also had very high levels of serum alkaline phosphatase and high bone turnover. Her bone mineral density evaluation by dual energy x-ray absorptiometry showed osteoporosis in the lumbar spine and osteopenia in femoral neck. Skull radiographs and a further bone scintigraphic study with Tc-99m methylene diphosphonate revealed Paget disease. Successful parathyroidectomy was performed and a parathyroid adenoma was removed. On reevaluation, no evidence of residual hyperparathyroidism was found. Bone metabolism was improved but remained disordered. The patient was then treated with IV zolendronic acid.