Central diabetes insipidus (CDI) is the most common manifestation of central nervous system involvement in Langerhans cell histiocytosis (LCH). Therefore, in patients with endocrinologically proven CDI, a comprehensive diagnostic evaluation is crucial to identify possible extracranial sites of LCH. However, once established, DI is mostly associated with life-long dependence on antidiuretic hormone (ADH) replacement therapy. We here report 3 cases of CDI in association with LCH, diagnosed by a water deprivation test. Two patients who presented with CDI as the initial manifestation showed thickened pituitary stalk on the sellar MRI. The 3rd patient developed CDI as a late sequela of LCH. Regression of pituitary thickness on MRI did not correlate with the clinical recovery of CDI, as shown in 2 cases.