Ecstasy (methylenedioxymethamphetamine, mdma) is a synthetic drug which is popular among clubbers who love it for its euphoric and energizing effects. These subjective effects are experienced approximately between one and four hours after intake. It is also shown that mdma affects driving-related behavior, as measured by performance tasks and simulated driving, as well as actual driving as assessed by on-the-road driving tests. Under optimal conditions that are during daytime, moderate doses, and with no co-use of other substances mdma exerts stimulating effects on reaction time performance, tracking and weaving. However, when mdma is combined with alcohol or sleep deprivation, these stimulating effects are no longer observable. Combined use of mdma with cannabis or alcohol is common among ecstasy users. In addition, they usually take the drug at night and drive in the morning after a night of partying and sleep loss. Experimental data have shown that the stimulating effects of mdma are not of sufficient magnitude to compensate for the impairing effects of sleep loss. Moreover, subjective data have shown that ecstasy users are not able to accurately estimate their objective impairment when under the influence of mdma. Their lack of judgment during intoxication can put them at risk when engaged in traffic. Epidemiological studies and case studies have also shown that mdma at normal doses (75 mg) is able to impair driving performance which is characterized by reckless behavior such as speeding and jumping red traffic lights. In addition, in a number of fatalities, ecstasy was detected in the blood of the driver. In sum, mdma can exert stimulating effects on some aspects of driving when given at low doses. However mdma is likely to produce driving impairment in combination with other drugs or during a night of sleep loss as is often the case in regular ecstasy users.keywordssleep deprivationecstasy userdrug alcohol dependthese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.