OBJECTIVES: We sought to determine occurrence, predictors, and prognosis of alcohol withdrawal syndrome and delirium tremens in patients with traumatic injury. DESIGN: Retrospective multicenter cohort study. SETTING: Three U.S. trauma centers. PATIENTS: Twenty-eight thousand one hundred one trauma patients admitted from 2010-2014. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Measures included occurrence of alcohol withdrawal syndrome and delirium tremens, injury characteristics, risk factors for alcohol withdrawal syndrome, clinical outcomes, pharmacologic treatment for alcohol withdrawal syndrome, and Clinical Institute Withdrawal Assessment for Alcohol, Revised (CIWA-Ar) scores. Alcohol withdrawal syndrome severity was defined by CIWA-Ar score as minimal (< 10), moderate (10-20), and severe (> 20). Alcohol withdrawal syndrome developed in 0.88% (n = 246), including 12% minimal, 36% moderate, and 53% severe. Alcohol withdrawal syndrome progressed to delirium tremens in 11%. Before adjustment, alcohol withdrawal syndrome severity was associated with injury severity, hypokalemia, baseline CIWA-Ar score, and established alcohol withdrawal syndrome risk factors. Logistic regression identified the following predictors of delirium tremens: baseline CIWA-Ar score greater than or equal to 10 (odds ratio, 6.05; p = 0.02) and age greater than or equal to 55 (odds ratio, 3.24; p = 0.03). In patients with severe alcohol withdrawal syndrome, severe head injury also predicted progression to delirium tremens (odds ratio, 6.08; p = 0.01), and hypokalemia was borderline significant (odds ratio, 3.23; p = 0.07). Clinical outcomes of hospital length of stay, ICU length of stay, and alcohol withdrawal syndrome complications differed significantly by alcohol withdrawal syndrome severity and were worse with more severe manifestations of alcohol withdrawal syndrome. Mortality also significantly differed by alcohol withdrawal syndrome severity but was only greater in patients who progressed to delirium tremens (11.1%; p = 0.02); otherwise, there were no differences in mortality by severity (4%, 4%, and 0% by minimal, moderate, and severe alcohol withdrawal syndrome). CONCLUSIONS: Trauma patients with alcohol withdrawal syndrome experience a high occurrence of delirium tremens that is associated with significant mortality. These data demonstrate the predictive ability of baseline CIWA-Ar score, age, and severe head injury for developing delirium tremens.