This paper is based on a retrospective study of 230 tumours in the sellar area. All, except a few, were examined with the EMI 160 x 160 matrix and verified histologically. The main features of each pathological entity are described and most of the previous literature is reviewed. The degree of resolution of the scanner used precludes its reliability for detecting tumours less than one centimetre in diameter. Out of 30 microadenomas, only two were detectable on CT. This reflects an incidence of false negative results in 93% of microadenomas or 22% of all adenomas in the series. CT was also negative in 6% of craniopharyngiomas and 30% of chordomas. These findings emphasize the need for further neuroradiological tests in patients with clinically evident disease in the pituitary area. Many CT appearances are shared by more than one pathological entity; few are specific. However, if the CT findings are viewed in the light of the clinical presentation, a pathological diagnosis is possible in a large proportion of cases. Angiography is valuable; not only to exclude lesions of vascular origin, or show neovascularity, but also to demonstrate the relationship of the internal carotid arteries to the sphenoidal sinus prior to transsphenoidal surgery.