The diagnosis of sellar and parasellar tumors have been thought as relatively easy with detailed clinical history, neurologic findings, hormonal and radiologic studies, because of their characteristic neurologic features and specific endocrine disturbances. But sometimes location, nature, size and shape of the tumors and their relationship to adjacent tissues make it difficult to be determined even with various diagnostic aids. We have experienced 89 cases of sellar and parasellar tumors, excluding aneurysm and inflammatory lesions, during the last 16 years from August, 1958 to July, 1974 at the Department of Neurosurgery, Seoul National University Hospital. Among them we have studied 54 pathologically verified cases for various diagnostic studies. The results were as follows. 1. Detailed clinical history, hormonal studies and neurologic findings were fundamental in the diagnosis. 2. Simple skull x-rays were valuable to differentiate sellar and parasellar tumors and size. Shape and calcification of sella turcica were also valuable in differential diagnosis. Double floor shadow of sella turcica on exact simple lateral skull x-ray was very important to locate the tumor. 3. Bilateral carotid angiography and retrograde brachial angiography were important to differentiate the lesion, evaluate the size, extent and nature of sellar and parasellar tumors. The findings of terminal basilar artery were more important. 4. Air studies were valuable to know the extent of tumor and conray ventriculography was much valuable in differential diagnosis especially for obstructive hydrocephalic cases.