Twenty patients with the typical clinical presentation of Sheehan's syndrome were studied. All had a severe degree of hypopituitarism. The circulating mean basal levels of thyroid hormones, cortisol and prolactin were significantly lower (p < 0.05 to < 0.02) compared to those in 50 age matched controls. The provoked pituitary responses to combined pituitary stimulation in 13 patients were markedly lower (p < 0.02 to < 0.001) than those in ten age matched control subjects. Sellar computed tomography revealed an empty sella in all the patients; partial in five and complete in the remaining. A secondary empty sella is considered a characteristic finding in the classical form of Sheehan's syndrome.