AbstractPrevious research has identified general personality traits and personality disorders that are associated with externalizing behaviour (EB). There is a dearth of research, however, investigating the relations between pathological personality traits and EB. The current study examined pathological personality traits, as measured by the Schedule for Non‐adaptive and Adaptive Functioning (SNAP) and the Dimensional Assessment of Personality Pathology‐Basic Questionnaire (DAPP‐BQ), in relation to EB. Undergraduates (n = 228) completed the SNAP, DAPP‐BQ, and a measure of antisocial behaviour, substance use, gambling, intimate partner violence and risky sexual behaviour. Using confirmatory factor analysis, we identified the best fitting model as one that specified eight factors: five personality factors composed of constructs assessed by the DAPP and SNAP, one externalizing factor and two method factors corresponding to each of the measures. Consistent with the empirical literature using general personality traits, the current results suggest that pathological personality traits related to impulse control (i.e. low conscientiousness), as well as more interpersonally focused traits (i.e. low agreeableness), were most strongly associated with EB. Copyright © 2009 John Wiley & Sons, Ltd.