Pharmacological and metabolic effects of ashwagandha (Withania somnifera L. (Solanaceae)) used in Ayurveda as a herbal tonic and health food were studied. Ashwagandha was shown to increase swimming time in rats in physical working capacity test, i.e. rats swimming endurance test. Significant increase in relative heart weight and glycogen content in myocardium and liver was also observed in ashwagandha treated group. Ashwagandha treatment increased the duration of contractility in functional test for the resistance of frog heart muscle towards the toxic action of strophanthin-K. Ashwaaandha treatment also resulted in significant increase in coagulation time which attains normalcy 7 days after cessation of treatment. Ashwagandha possesses no toxicity up to a dose of (100 mg/kg; p.o. for 180 days) and does not cause significant changes in biochemical parameters in the blood serum of rats. Increase in catecholamine content in the heart and aortic tissues and their decrease in adrenal glands are unfavourable effects of high doses of ashwagandha. On the basis of these observations, it was concluded that ashwagandha possesses adaptogenic, cardiotropic, cardioprotective and anticoagulant properties.