Lorazepam is of value in the performance of gas encephalography. Given with judicious and individualized doses of IV narcotic, it has significantly lessened the morbidity of this examination. We have been particularly impressed with the lack of unpleasant memories for the procedure. The quality of the examination was good through the patients had to be reminded, because of the amnestic effects of the drug, to hold still throughout the 6-s exposure needed for polytomography.