The management of severe hyponatraemia is a challenging task for intensivists. It should be based on underlying pathophysiology, especially the duration of hyponatraemia (acute vs. chronic) and the presence or absence of severe neurologic symptoms. We describe a case of severe community-acquired hyponatraemia in which central pontine myelinolysis developed several days after discharge from the intensive care unit, despite a gradual increase of plasma sodium levels during the intensive care unit stay.