In the late 1990s, the large metropolitan area of Seattle, OR experienced a rise in the use of MDMA (ecstasy), and to a lesser extent, other club drugs among youth and young adults. For the purpose of this study, seven data sources were utilized to examine the extent of MDMA use and the patterns of MDMA use in the city of Seattle. The seven data sources included: local community-based club drug surveys collected in 2003 at raves, treatment agencies and gay-oriented bars and sex clubs; school surveys collected in 2002; mortality data (between 2000 and 2002); data from the sexually transmitted disease clinic (2002-2003); focus groups (2003) with men who have sex with men; emergency department drug mentions (1995 to 2002); and drug treatment admissions (1999 to 2003). The data indicate moderate levels of MDMA use and relatively low levels of mortality and acute morbidity. The findings have many ramifications in the areas of prevention, intervention, and treatment efforts. Glossary and references