A CT scan study of the sella turcica and its contents was conducted in patients with Sheehan's syndrome with a search for correlation between the radiological data and the degree of endocrine insufficiency on one hand, and the time course of the disease on the other. Fifty-four patients with Sheehan's syndrome were included: 32 with complete anterior hypopituitarism, 22 with at least one spared pituitary function. Subgroups of equal size were obtained with a cut-off of 9 years evolution. The CT scan appearance of the pituitary was never normal in Sheehan's syndrome. The sella turcica was totally empty in 39 patients. A pituitary remnant was visible in 15 patients, more frequently in those with incomplete hypopituitarism (p less than 0.005) and those with short evolution (p less than 0.025). The size of this pituitary residue never exceeded one third of the normal pituitary gland. The pituitary stalk was always visualized. On the other hand, the size of the fossa was significantly (p less than 0.001) smaller in the patients, as compared to a 12-female control group, matched for age and number of pregnancies. Among the patients there was no difference when considering the disease duration nor the degree of hypopituitarism. An empty or partially empty sella of normal or reduced size is a constant feature of Sheehan's syndrome. The presence of a pituitary remnant is inversely correlated to the duration and extension of the disease. Arachnoid herniation alone does not induce a dilatation of the fossa.