Although ecstasy has enjoyed a reputation as an enhancer of sexual performance in the media, little research has examined the effects it has on sexual behaviour. As part of a larger survey involving personal interviews with 213 ecstasy users, the HIV Risk-taking Behaviour Scale (HRBS) was administered to examine extent of sexual risk-taking while intoxicated and not, along with items concerning the effects of ecstasy on sex. Results indicated that 77% of the sample had engaged in penetrative sex in the preceding month and that 49% had had sex while intoxicated in the preceding six months. There was a tendency to use condoms less often with casual partners while intoxicated than while not. Ecstasy use and age were more consistent predictors of sexual risk-taking than gender and sexual identity. Most subjects reported that ecstasy improved sex (70%) and lowered inhibitions (67%). However, 45% also reported that ecstasy inhibited arousal and/or climax. Twelve percent reported a loss of sex urge related to ecstasy use in the preceding six months, lasting for an average of 48 hours. Results suggested that the effects of ecstasy on sex are idiosyncratic and that better education on the risks of unsafe sexual activity for ecstasy users is warranted.