Data were obtained every 2 years from multiple sources, including specialist treatment centers, trauma units, school students, "rave" party attendees, and from police and arrestees. Across most sites, treatment demand for Ecstasy as the primary drug of abuse was stable at 1 percent to 3 percent of the total demand for alcohol and drug treatment. Ecstasy was frequently reported as a secondary drug of abuse and was frequently used in combination with other substances. The overall proportion of patients who reported using Ecstasy as either a primary or secondary drug of abuse remained stable in Gauteng at 5 percent and increased in Cape Town from 2 percent in 1999 to 9 percent in the second half of 2001. Among Ecstasy users, White South African youth of both genders predominated, with the age of users decreasing over recent years. Although there have been a few well-publicized media reports of deaths due to Ecstasy-toxicity in South Africa, accurate and comprehensive data on the negative health consequences of Ecstasy use were not available; however, data indicate that Ecstasy use currently places a relatively small burden on the health and social welfare systems of the country. Protocols should be established for the identification and management of patients in general hospitals and trauma units who suffer from Ecstasy-related toxicity, and age-appropriate prevention programs must be developed. 3 tables and 22 references