Three cases of pituitary abscess are presented. The history of recurrent attacks of aseptic meningitis, together with radiological and clinical features suggestive of pituitary tumor, appear to form a fairly typical picture of the condition. Long follow-up was possible in two of the cases. There are no radiological features which distinguish the lesion from pituitary tumor, hence the importance of recognizing the significance of such a clinical presentation with radiological evidence of sellar enlargement. Pituitary abscesses seem to occur in preexisting pituitary tumors. The possible relationship with pituitary infarction is discussed.