Central diabetes insipidus (DI) is a rare disease in children. The authors retrospectively reviewed the records of children with central DI identified at Songklanagarind Hospital from 1985 to 2000. Of the total 29 patients identified, 16 patients were males and 13 were females. All patients received computed tomography or magnetic resonance imaging of the brain to differentiate the etiologies of central DI. The median age at diagnosis was 6.6 years (range 1.5-14.9). The etiologies of central DI were intracranial tumors in 7 patients (24.1%), histiocytosis in 3 patients (10.3%), septooptic dysplasia in 1 patient (3.5%), empty-sella syndrome in 1 patient (3.5%), pituitary abscess in 1 patient (3.5%), and idiopathic in 16 patients (55.1%). All patients with idiopathic central DI were followed-up for a median duration of 4.5 years (range 1.3-15.5). Three of 16 patients (18.8%) were found to have intracranial tumors at 1.3, 2.3, and 3.5 years of follow-up. It was also observed that the patients whose age at presentation was less than 5 years (histiocytosis was excluded) were less likely to have intracranial tumors than those older than 5 years, (0% vs 55%), with significant statistical difference (p<0.01). It is concluded that: 1) the common etiologies of central DI are intracranial tumor and idiopathic, 2) patients initially diagnosed with idiopathic central DI need to have long-term follow-up by magnetic resonance imaging to identify any occult intracerebral tumor.