Quantitative determinations of glycogen of periportal and centrilobular cells of the liver were made in normal, fasted, realimented and cortisone-treated rats. In most instances there was no significant portal-central difference in glycogen concentration. There were two exceptions. After 2 hr of refeeding following a 24-hr fast, the central to portal glycogen ratio was 1.3. During recovery from the glycogen overshoot, which occurs upon feeding after a prolonged fast, portal glycogen exceeded central glycogen by a factor of 1.8. It is suggested that some of the discordant staining findings on glycogen distribution arise from artifacts.