 MDMA is a psychoactive drug that has been increasingly abused worldwide, due to its entactogenic properties. However, concerns on its safety exist, particularly regarding its effects on attentional skills and performance. Evidence from the literature shows contrasting effects of MDMA. It generally acts as a pshychomotor stimulant, thus improving arousal and psychomotor function. However, MDMA has been demonstrated to negatively influence other skills. Consequently, human activities that require alertness, and accurate and quick reflexes (i.e. driving, operations at the workplace, etc.) could be negatively affected. In the present study, the effect of MDMA (0.1–20 mg/kg, intraperitoneally) on sensorimotor and startle/prepulse inhibition responses was evaluated in a controlled rodent experimental setting.