Recent studies show a high prevalence of traumatic events in samples of patients with a substance use disorder. In the present study, the lifetime exposure to potentially traumatic events (PTEs) was estimated in a sample of 458 patients recruited at 17 randomly chosen alcohol-dependence treatment units in the public healthcare sector in Poland. Eighty percent of the patients reported a history of at least one potentially traumatic event. Sixty percent of them reported experiencing more than one probable trauma. However, only the patients who experienced physical assault reported worse clinical severity in posttraumatic stress and alcohol-use related symptomatology. The findings confirm the importance of trauma assessment in alcohol-dependent patients and the inclusion of trauma-related issues in the treatment of alcohol dependence.