Erdheim–Chester disease (ECD) is a rare non-Langerhans disease. This report describes a 51-year-old woman with a history of weakness, bone pain, xanthelasma palpebrarum, diabetes insipidus, and hypothyroidism. ECD is a multisystemic condition with a poor prognosis. This disease should be considered in patients with diabetes insipidus and multiorgan involvements.