ABSTRACT:The purpose of this study was to evaluate antistress activity of roots of Diospyros malabarica (Desr.) Kostel (DMDK) against anoxia stress tolerance, chemical induced stress, swimming endurance stress and immobilisation stress models in mice and rats. Ethanolic extract of roots of DMDK (EERDMDK) was screened for its antistress activity at 125 mg/kg, 250 mg/kg, 500 mg/kg, p.o. doses and diazepam was selected as reference standard at 2 mg/kg i.p. dose. Stress was induced by anoxia stress tolerance, chemical induced, swimming endurance and immobilisation stress models in mice and rats. The antistress activity was evaluated by measuring anoxia stress tolerance time, number of writhes, immobility time, organs weight of animals and estimating biochemical parameters such as glucose, cholesterol and blood urea nitrogen. Pretreatment with EERDMDK showed significant increases in anoxia stress tolerance time and significant decreases in number of writhes and immobility time in mice and this effect was dose dependent when compared to control. In immobilisation stress model pretreatment with EERDMDK showed significant reduction in level of biochemical parameters such as glucose, cholesterol and blood urea nitrogen, whereas stress induced increase in liver, adrenal gland weight and decrease in weight of spleen were significantly reversed by EERDMDK in dose dependent manner i.e. EERDMDK restored weight of organs and level of biochemical parameters when compared to positive control. The conclusion of our study indicated that EERDMDK possessed significant antistress activity and possible mechanism underlying this effect is mediated through normalization of catecholamines level.