A sample of 398 undergraduate students completed questionnaires assessing the main constructs of the theory of planned behaviour (TPB) in relation to binge drinking, as well as past binge drinking behaviour. Of these, 273 were followed up at 1 week. Regression analyses revealed attitude, self-efficacy, and perceived control (negative relationship) to be predictive of binge drinking intentions. Intention and self-efficacy were, in turn, predictive of binge drinking at 1-week follow-up. Past behaviour was found to explain additional variance in intention and behaviour. In addition, past behaviour was found to moderate the attitude–intention and intention–behaviour relationships, such that weaker relationships were observed with increasing frequency of past behaviour. The results are discussed in relation to the need to develop and test alternative measures of habit. The implications of the findings for interventions to encourage more appropriate drinking behaviour are outlined.