Alcohol consumption is a major contributor to global morbidity and mortality, necessitating public health interventions. This study, approved by the University of Cambridge, explored the impact of reducing wine serving sizes in licensed premises in England. Employing an A-B-A treatment reversal design, the study involved 21 establishments over twelve weeks, alternating between standard and reduced wine serving sizes. The intervention involved removing the largest serving size of wine glasses, and its effects were measured in terms of wine and beverage sales and total revenue. The findings indicated a 7.6% reduction in wine sales volume without affecting the sales of other beverages or overall revenue, suggesting that smaller serving sizes may effectively reduce alcohol consumption. This approach did not lead to an increase in consumption of other alcoholic beverages or changes in revenue, indicating its potential as a public health strategy. The study’s limitations include its focus on wine sales and its limited generalizability due to the specific context and premises involved. Nonetheless, these findings suggest that reducing serving sizes in alcohol sales could be a promising intervention for public health, meriting further research and consideration in policy-making.