Abscess formation in the pituitary gland is very rare. The development of such a lesion is through to be due to direct extension of adjacent infection or metastasis remote lesion. It has been suggested by some authors that intrinsic lesions of the pituitary gland may favor the development of infections. Tumors and postpartum necrosis of the pituitary gland are the lesions which easily undergo secondary infection. Recently we experienced a case of pituitary abscess. A 27 years old housewife was admitted to our hospital because of intermittent headache, constricted visual field and amenorrhea of about 3 years' duration. Clinical manifestations and diagnostic studies strongly suggested pituitary tumor. Upon surgery, abscess was found in the pituitary fossa. Direct smear of the aspirated material showed many polymorphous leukocytes. No microorganisms were detected on direct smear and in culture. Biopsy of the capsule demonstrated nonspecific of the pituitary gland. There developed transient polydipsia and polyuria postoperatively but soon disappeared under medication of Esidrex. Our case of pituitary abscess is interesting in that it's main symptoms developed after delivery, which suggests Sheehan's syndrome followed by abscess formation.