Personality characteristics have been linked to substance use, however research on the association between personality and MDMA use is scarce. This study examined differences on Big Five personality dimensions between a population sample of non-hard drug using Dutch adolescents and young adults (n=265), and a sample of young people visiting house parties, including both MDMA- and non-MDMA-users (n=541). Results showed that 71% of the party visitors indicated using MDMA. Group differences were found on conscientiousness, extraversion, agreeableness and neuroticism-emotional stability, but not on resourcefulness-openness to experience. Compared to the non-hard drug using National respondents, MDMA-using party visitors reported higher levels of extraversion and both MDMA and non-MDMA-using partygoers showed less conscientiousness. Non-MDMA-using partygoers reported less agreeableness and emotional stability than National Sample respondents. MDMA-users actually high on the drug at the moment of administration of the questionnaire did not differ from their non-high counterparts on any of the personality dimensions.