The aim of the present study was to evaluate the protective effect of ginseng total saponin, panaxadiol and panaxatriol, which are the major components of Panax ginseng, against myocardial ischemia/reperfusion (I/R) injury in isolated rat hearts. Rats were orally administered once a day with total saponin (20 mg/kg), panaxadiol (5 mg/kg) and panaxatriol (5 mg/kg) for consecutive 7 days. On day 8, the hearts were isolated and perfused with Krebs-Henseleit bicarbonate buffer solution using Langendorff apparatus. After 30 min of global ischemia, hearts were reperfused for 30 min. Myocardial function, coronary flow and biochemical parameters, such as lactate dehydrogenase (LDH), creatine kinase (CK), adenosine triphosphate (ATP), malondialdehyde (MDA) and reduced glutathione (GSH) were measured. Total saponin and panaxatriol significantly improved I/R-induced myocardial dysfunction by increasing left ventricular development pressure, (-dP/dt)/(+dP/dt) and time to contracture. Moreover, the increases in the levels of LDH, CK and MDA and the decrease in the levels of GSH were attenuated by total saponin and panaxatriol. However, the ATP levels did not affected by total saponin, panaxadiol and panaxatriol pretreatment. Our findings suggest that pretreatment with ginseng total saponin, especially panaxatriol, ameliorates I/R-induced myocardial damage and this protection is caused by reducing oxidative stress.