Objective: This study examines student alcohol use and associated problems, including drinking and driving, at U.S. colleges that ban alcohol for all students on campus. Method: A nationally representative sample of students (N = 11,303, 61% women) attending U.S. colleges completed questionnaires regarding alcohol use and related behaviors in the spring of 1999. The responses of 2,252 students at 19 ban schools were compared with those of 9,051 students at 76 nonban schools. Results: Students at ban colleges were 30% less likely to be heavy episodic drinkers and more likely to abstain from alcohol. The lower rates of heavy episodic drinking apply to students whether or not they were heavy episodic drinkers in high school. However, among drinkers, students at ban schools engaged in as much extreme drinking as drinkers at schools that do not ban alcohol and experienced the same rate of alcohol-related problems. At schools that ban alcohol, fewer students experienced secondhand effects of the drinking of others than did students at nonban schools. Students at ban schools were not more likely to drink and drive than were students at nonban schools. Conclusions: A campus ban on alcohol may support abstention from alcohol use and reduce heavy episodic drinking and the associated secondhand effects in college. Since this is a correlational study, we cannot determine whether the lower rates of heavy episodic drinking are due to the ban or to other factors (e.g., self-selection of students to these schools). Ban schools do not enroll fewer high school heavy episodic drinkers.