We assessed alcohol enforcement practices at 343 U.S. colleges via surveys of directors of campus law enforcement. We measured types and frequency of enforcement and barriers to enforcement. We found that 61% of colleges indicated nearly always proactively enforcing alcohol policies, with most frequent enforcement at intercollegiate sporting events and least frequent enforcement at fraternity/sorority events. Approximately half of the enforcement departments work closely with their local law enforcement agency but respondents indicated a greater need for cooperation with local law enforcement. Half of the respondents reported no barriers to alcohol enforcement on campus. Large colleges and public colleges tended to report greater enforcement levels. While many campuses report proactive alcohol enforcement, several areas of improvement in alcohol enforcement at colleges are indicated. (Contains 4 tables.)