This study evaluated the impact of screening with the AUDIT and of brief intervention (BI) on alcohol use in a sample of patients treated for opioid or cocaine dependence in a specialized outpatient clinic. 254 adult outpatients treated for opioid or cocaine dependence were screened with the AUDIT. Patients with scores that indicated excessive drinking or dependence were randomized into two groups–treatment as usual or treatment as usual together with BI and assessed at 3 months and 9 months. Findings showed a high rate (44%) of problematic alcohol use (excessive drinking and dependence). The number of drinks per week decreased significantly between inclusion and three months. A decrease in average AUDIT scores was observed between inclusion and three and nine months. In a substance abuse specialized setting, screening for alcohol use with the AUDIT, followed by feedback on the score, and use of alcohol BI are both useful strategies to induce changes in problematic alcohol use.