The distance between mitochondria and the nearest plasma membrane was measured in actively secreting and nonsecreting exocrine glands in order to determine the effect of the secretory mechanism upon mitochondrial distribution. The greatest accumulation of mitochondria was at 0.6 µm from the plasma membrane. No difference was noted in mitochondrial distribution of actively secreting, untreated and atropine-treated animals. There was also no difference in mitochondrial distribution of lacrimal and parotid acinar cells. The possible physiological significance of this observation is discussed