Physiologically, two complementary mechanisms regulate plasma osmolality: antduretic hormone ADH) and thirst. ADH release s supressed, thirst s inhbted and renal water loss occurs when plasma osmolality below a threshold level. The rise in plasma osmolalty causes ADH release, stimulation of thirst and water intake. Acute water intoxication is exceptional in patients without a chronic psychiatric disease. Herein, we describe a case of acute water intoxication in a previously healthy patient, after making an intravenous urography. The excessive water intake and the impossibility of renal water loss because of streee-induced ADH release originated t. Only nine cases have been previously described; almost they all were women preparing for diagnostic procedures.