Excessive alcohol consumption and sexual risk taking can create considerable risks to ones own health and the health of others, therefore increased understanding of possible risk factors is needed to inform health- related prevention interventions (i.e. HIV prevention and alcohol use prevention). The present study aims to investigate the associations between: personality and alcohol consumption, personality and sexual risk taking, and alcohol consumption and sexual risk taking behaviour. Data for this study was obtained from 196 undergraduate students from a variety of courses. The self-administered questionnaires aimed to assess psychosocial factors, alcohol consumption and sexual risk taking. The results showed an association between personality and alcohol consumption. Men who obtained higher sensation seeking scores tended to drink more alcohol units per week than men with lower sensation seeking scores (p<.01) and men who reported lower levels of intellect/imagination were more likely to binge drink (p<.01). For women, it was shown that high sensation seeking, high extraversion and low conscientiousness were predictors of alcohol consumption. In multiple regression analysis, men who were less agreeable were found to be more likely to engage in sexual risk taking behaviour (accounting for 8% of the variance), even after alcohol consumption was controlled for. In women, higher sensation seeking scores predicted sexual risk taking behaviour accounting for 8% of the variance, however, when alcohol consumption was included in the model, alcohol consumption alone accounted for 13% of the variance in sexual risk taking behaviour. This study provides evidence for a personality-based theory in men. In women, alcohol consumption was a direct predictor of sexual risk taking, and may be viewed as a partial mediator between personality and sexual risk taking.