Similar to other sociological studies of Ecstasy use, the authors' research suggests that Ecstasy users tend to report positive effects of the drug. However, we also observed that most users experienced at least one adverse psychological outcome while using Ecstasy. The present study examines those negative experiences within the context of drug, set and setting. Data were collected through in-depth interviews with 98 current or former users of Ecstasy. The results indicate that, in general, negative experiences with Ecstasy did not deter people from using the drug again. The findings suggest that most negative experiences with Ecstasy can be attributed to the interaction between two or more factors, nearly always involving set or setting. Although various analyses have shown that the same "brand" of Ecstasy can contain varying degrees of MDMA, other drugs and adulterants, results from the present study suggest that users' expectations of the drug's effects appear to be related to the brand or label of Ecstasy that is consumed. The role of individual disposition in producing negative drug experiences is less clear; it is possible that this factor might interact with user set or friends' set in contributing to the overall drug experience.