Alcohol-positive trauma patients are more likely to be readmitted to a trauma center or subsequently die from an injury than are alcohol-negative patients. Empirically supported treatments to reduce alcohol use and alcohol-related problems (e.g., injuries, drinking and driving) in this high-risk population are needed, but few exist. This randomized controlled clinical trial assesses the efficacy of a brief intervention that includes the patient and a significant other, relative to an intervention including the patient only, for reducing alcohol use and alcohol-related problems among trauma patients.