: Pituitary stalk interruption syndrome (PSIS) is a congenital disease with isolated growth hormone deficiency (GHD) or multiple anterior pituitary hormone deficiencies (MPHD). The typical clinical manifestations of PSIS are growth retardation, hypoglycemia or delayed pubertal development. However, few reports showed cases of PSIS were diagnosed with acute epileptic seizures accompanied by hyponatremia. Here, we report an 18-year-old female presenting with episodes of intermittent seizures for 13 years. The electrolyte examination on many occasions has shown hyponatremia, even as low as 99.9 mmol/L. However, the cause of hyponatremia has not been further discussed. The patient had short stature and no pubertal development. The laboratory tests revealed growth hormone deficiency, secondary adrenal insufficiency, hypothyroidism and hypogonadotropic hypogonadism. MRI showed an ectopic hyperintense signal of the posterior pituitary and no visible anterior pituitary gland or stalk. The hormone replacement therapy helped to raise the sodium concentration to a normal level and in the termination of seizures.