A random sample of more than 15,000 undergraduate students from 130 4-year colleges answered a mailed questionnaire concerning firearm possession. Approximately 3.5% of the sampled students reported they had a working firearm at college. Students with guns were more likely to be male, White, or Native American; to binge drink and need to start the day with alcohol; to be members of a fraternity or sorority; to live off campus; and to live with a spouse or significant other. Having a gun was positively associated with driving after binge drinking, being arrested for driving under the influence of alcohol, and damaging property as a result of alcohol ingestion. Students with guns were also more likely to be injured severely enough to require medical attention, especially for injuries occurring in fights or car crashes. Overall, students with guns at college were more likely than others to engage in activities that put themselves and others at risk for injury.