Adipsic diabetes insipidus (ADI) is a rare form of central diabetes insipidus characterized by hypotonic polyuria associated with absent or impaired thirst, causing a devastating disorder of water balance with significant associated morbidity and mortality. Adipsic diabetes insipidus results from injury to osmosensitive neuroreceptors, mainly located in the paraventricular and supraoptic nuclei, which leads to reduced synthesis and secretion of arginine vasopressin. Key neural circuits governing thirst perception and drive are anatomically colocalized with arginine vasopressin-producing centers and are therefore affected by the same injury, leading to impaired thirst and severe water balance dysregulation. In most patients, the disease arises from destruction of the hypothalamus due to a variety of underlying causes. Adipsic diabetes insipidus has most frequently been linked to surgical clipping of anterior communicating artery aneurysms after subarachnoid hemorrhage, as well as to craniopharyngioma and certain congenital disorders. Meanwhile, suprasellar arachnoid cysts are an uncommon cause. In this case, the suprasellar arachnoid cyst was responsible for hypothalamic-pituitary compression. Diagnosis relies on clinical suspicion, biochemical findings, and imaging. Adipsic diabetes insipidus is a rare but serious condition requiring early recognition. Although often asymptomatic, suprasellar arachnoid cysts can lead to this complication. Management is based on combining hormonal therapy such as arginine vasopressin replacement, careful fluid management, and etiological treatment. Furthermore, keeping serum sodium levels within the normal range is often difficult in these patients, and marked fluctuations in sodium levels frequently lead to recurrent hospitalizations. Thus, a multidisciplinary approach is essential to prevent severe complications and improve outcomes.(Kothari et al., 2021a) (Blevins & Wand, 1992)