Objective: High-risk alcohol use among college students has received substantial attention in recent years, and intervention and prevention efforts have increased dramatically. The current study examined ADHD as a risk factor for problematic drinking among college students. Trait disinhibition and difficulty stopping a drinking session were examined as potential mechanisms through which ADHD is associated with alcohol-related problems. Method: Participants included 100 full-time undergraduate students with (n = 48) and without (n = 52) Diagnostic and Statistical Manual of Mental Disorders (4th ed.) ADHD. Results: Students with ADHD had higher rates of alcohol-related problems and alcohol-use disorders across multiple measures. Both disinhibition and difficulty stopping a drinking session independently mediated the relationship between ADHD and negative consequences of alcohol use. Conclusion: These findings indicate that college students with ADHD are at increased risk for alcohol-related problems. Trait disinhibition and difficulty stopping a drinking session represent mechanisms of high-risk alcohol use among college students with ADHD.