In modern day health care, Sheehan's syndrome is a rare disorder affecting the postpartum period. We present a case of a 33-year-old woman with atonic hemorrhage developing a transient Sheehan's syndrome associated with hyponatremia six days postpartum. Evaluation of cranial computer tomography and magnetic resonance imaging of the pituitary demonstrated normal finding. Immediate replacement therapy using sodium, chloride, hydrocortisone, fludrocortisone and levothyroxine revealed regression of the Sheehan's syndrome to complete recovery. The present report shows that Sheehan's syndrome can be associated with hyponatremia and illustrates the need to include hyponatremia as an initial symptom in the differential diagnosis of Sheehan's syndrome.