This research discusses the use of social norms marketing to improve responsible drinking among college students. It was observed in each year of research that students studied overestimated their peers’ drinking practices. During the social norms marketing campaign decreases were observed in both students’ self-reported number of drinks consumed and perceived number of drinks consumed by peers at bars or parties, indicating that the social norms marketing efforts were somewhat successful. In addition, students reported drinking less alcohol over a shorter period of time. However, some negative behaviors related to drinking did not improve.