To describe a case of primary bacterial pituitary abscess manifesting as hypopituitarism. We present the case history, hormonal and bacteriologic data, and findings on imaging studies in a 34-year-old man. The patient had an 8-month history of intermittent fever, headache, nausea, vomiting, and weight loss. Because a computed tomographic scan of the head showed a cystic sellar mass with ring enhancement, he was referred to our medical center. On physical examination, he showed signs of meningeal irritation and had mild hypotension. Hormonal evaluation revealed evidence of hypocortisolism, hypothyroidism, and hypogonadism. Three weeks after treatment with antibiotics and hormonal replacement, he underwent transsphenoidal surgical exploration and evacuation of purulent material from the sella. On culture, this specimen grew coagulase-negative staphylococci and Propionibacterium granulosum. Nine months later, dynamic testing showed persistent central hypocortisolism, hypothyroidism, and hypogonadism. Bacterial pituitary abscess is rare but manifests similar to other pituitary masses with headaches, visual field defects, and hormonal disturbances. For the correct preoperative diagnosis of this condition, the physician must have a high index of suspicion, and the characteristic ring enhancement must be present on imaging studies.