Pathogenesis of idiopathic diabetes insipidus is unknown and the clinical course of the disease is permanent. However, we observed one patient who was diagnosed of idiopathic diabetes insipidus spontaneously reverted after approximately 13 months. The cause and pathogenesis of the disease were not evident. However, some reversible abnormalities should have been encountered in the hypothalamic-neurohypophyseal system. It is suggested that some unknown reversible impairments of the supraopticohypophyseal tract can cause diabetes insipidus. This case represents a well-documented description of idiopathic diabetes insipidus with spontaneous remission.