In human, ingestion of ecstasy (MDMA) has been associated with acute adverse reactions such as hyperthermia, hypertension and tachycardia. Little is known about what exactly MDMA does to those physiological responses. We, therefore, investigated acute effects of MDMA on cardiovascular and respiratory responses in female rats. Invasive arterial blood pressure, heart rate and respiratory rate were recorded in pentobarbital-anaesthetized female rats for 2 hours after single i.v. injected with vehicle (n=6), 5 mg/kg MDMA (n=7) and 10 mg/kg MDMA (n=8). Intragroup comparison showed that MDMA markedly increased mean arterial blood pressure (MABP) and systolic blood pressure immediately after MDMA administration (p<0.05, compared to baseline). In comparison between groups, significant and non-dose-dependent increases in MABP, systolic blood pressure and diastolic blood pressure can be observed immediately, 1 minute and 2 minutes after MDMA (p<0.05, two way repeated measures ANOVA). However, there were no changes in those parameters over the rest period of investigation. Heart rate was significantly increased 2, 3, 4 minutes after MDMA (p<0.05, compared to control). Interestingly, significant increase in respiratory rate was found in 10 mg/kg MDMA group at 2, 5, 10, 15 and 20 minutes after MDMA, whereas significant decrease was observed in 5 mg/kg MDMA group at 70, 80, 105 and 120 minutes after MDMA (p<0.05, compared to control). In conclusion, this study provided the first evidence of transient cardiovascular response (increases in MABP, systolic blood pressure, diastolic blood pressure and heart rate) and prolonged effects on respiratory response following acute MDMA in anesthetized female rats.