Shortage of water supply is the most important stress condition that can meet man and animals. Since the adrenal gland plays a pivotal role in the stress response, the aim of our work is to study, in the male Wistar rat, the effects of chronic dehydration on adrenal gland structure compared to that of a desert rodent: Gerbillus tarabuli . Adults and male Wistar rats and gerbils were divided into: i) control rats (n=8) given free access to tap water); ii) dehydrated rats (n=8) given 2% NaCl solution ad libitum for 7 days and (iii) G.tarabuli (n=6) given barely seeds ad libitum without access to water. Chronic dehydration caused strong adreno-chromaffin cells degranulation in rats. For the gerbils, adrenal zona fasciculate and medulla features suggest respectively an increased production and releases of glucocorticoides but a basal stress hormones release. These results suppose that shortage of water in arid environment does not constitute a stress factor for this specie.