A theory-based intervention aimed at reducing corporate employees' alcohol consumption in excess of guideline limits is presented. The intervention adopted an outcome mental simulation technique and was administered to a sample of corporate employees from three companies. A single-arm randomized-controlled design was adopted. All participants completed baseline psychological measures and self-reported number of alcohol units consumed and binge-drinking occasions. Participants allocated to the intervention condition were presented with a mental simulation exercise. One month later, participants completed follow-up measures of the psychological variables and alcohol consumption. Results revealed a significant effect of the mental simulation intervention on number of units of alcohol consumed at follow-up. There was no effect of the intervention on frequency of binge-drinking occasions. There was no evidence for the mediation of the effect of mental simulations on alcohol consumption by the perceived behavioural control and motivation variables. Results support the efficacy of the mental simulation intervention in reducing alcohol consumption but not in reducing binge drinking or alcohol consumption in excess of guideline limits, among corporate employees. Results are discussed with respect to the importance of the mental simulation intervention to inform practice and the proposed processes by which mental simulations affect alcohol consumption.