Sixteen patients with known cerebral disease had one- and two-hour delayed brain scans following intravenous injection of 15 mCi of technetium-99m glucoheptonate. No abnormalities were seen on the two-hour images that were not detected on the one-hour delayed scan. There were two false negative scans. Of the 14 true positives, 10 were visualized equally well in the one-and two-hour delayed images, two were better seen on two-hour images, and two were better on one-hour scans. As no difference in lesion detection was found, consideration of reducing the post-dose delay time two hours to one seems warranted.