This study found that levels of ecstasy use showed that it was less sporadic than often was assumed and also that it was common for users to take more than one pill. Younger users of ecstasy reported fewer days of use in the past 90 days. Those who subjectively ranked themselves in the higher socio-economic level tended to report using fewer days during the past 90 days. Aside from socio-demographic differences, numerous differences were found based on patterns of use. Oral ingestion of ecstasy remained the most common route. Those who used ecstasy with the greatest frequency or intensity commonly snorted, smoked, and injected the drug. The more intense user was more likely to report effects such as increased heart rate, an upset stomach, dehydration, visual distortions, and hallucinations. Those users who reported typically taking two or more pills to get high were more likely to do so around others who also did drugs. In regards to poly-drug use, those who used ecstasy most frequently were almost twice as likely to identify ecstasy as their primary drug of choice. Simultaneous poly-drug use (using ecstasy while using another drug) was common. A better understanding of ecstasy use patterns and combination and poly-drug use among young adults is needed with additional research recommended. Based on a cross-sectional survey, this study describes ecstasy use patterns among young adult users age 18 to 25 and compares these use patterns and effects according to the frequency of use (number of days used in the last 90 days) and intensity (number of pills taken) of ecstasy use. The survey was conducted between September 2002 and April 2004 and consisted of 261 current, out-of-treatment ecstasy users in Atlanta, GA. Tables, references