A technique for the removal of sphenoid blocks from cadavers and for selective injection of the hypophyseal arteries of these specimens is described. Results of such injections are presented, with emphasis on the role of the inferior hypophyseal artery (IHA). The IHA was found to be the most important artery supplying the pituitary gland, and in particular, the structures involved in production, transportation, and storage of the antidiuretic hormone. The literature pertinent to the arterial blood supply of the normal pituitary gland is reviewed.