Using data from the 1999 Monitoring the Future survey, the author examined and considered any demographic factors associated with ecstasy use reported within a sample of approximately 16,000 adolescents enrolled in the 10th grade in 130 public and private high schools across the United States. 7% of this sample reported having used ecstasy at least once in a lifetime, 5% reported ecstasy use within the previous year and 2% reported use in the previous month. Further comparisons were performed on the sample of 173 10th graders reporting ecstasy use in the past year or more and the 3145 10th graders reporting no ecstasy use. Ecstasy users were more likely than non-users to be White (97% versus 84%), more likely to be home alone for at least 3 h (28% versus 18%) and more likely to have used all other drugs examined in the survey, including alcohol (97% versus 61%, marijuana (87% versus 28%), powder and crack cocaine (36% versus 2%, 23% versus 1% and tranquilizers (35% versus 4%). Study findings indicate that unsupervised adolescents are more likely to use many substances, including ecstasy, and that 10th graders reporting ecstasy use are more likely to be White than non-White. However, in contrast to this last finding, Landry (2002) reported that high school students reporting ecstasy use were more likely to be Hispanic. Because Landry examined data from the 2000 MTF survey and since he also included lifetime use, it is possible that fluctuations in an already small number of respondents caused different ethnic profiles to arise. Study findings do not indicate that onset of ecstasy use occurs before onset of use of other substances. Adolescents who use ecstasy are also polydrug users.