Psychogenic polydipsia is a rare condition characterized by overconsumption of water. It can lead to water intoxication, which is potentially a life-threatening situation. Moreover, it usually occurs in patients with mental disorders, mainly schizophrenia. This report discusses a successful treatment of a 16-year-old male with psychogenic polydipsia and delusional disorder presenting to the emergency room with a hyponatremia-induced seizure. After stabilizing the patient, he was referred to a psychologist, and behavioral therapy was conducted. Post-discharge follow-ups revealed that behavioral therapy and the use of self-monitoring technique were effective in controlling the patient's condition. His water intake was reduced from 15 liters per day to three liters per day. This case highlights the importance of psychological assessment for patients with features suggestive of psychogenic polydipsia. It also highlights the need for immediate admission and prompt treatment for such patients as it is a high-risk condition.