Objective: To assess the specificity of the Adult ADHD Self-Report Scale (ASRS-v1.1) in detecting ADHD among individuals with substance use disorders (SUDs). Method: A chart review of 183 SUD patients was conducted. Patients were screened for ADHD with the ASRS-v1.1 and were later assessed by a psychiatrist specialized in ADHD. Results: Among SUD patients scoring positive results on the ASRS-v1.1 for the presence of ADHD, the ADHD diagnosis could only be confirmed in 26% of the sample by an expert psychiatrist. Conclusion: The ASRS-v1.1 reports low specificity in detecting ADHD among SUD populations. (J. of Att. Dis. 2011; XX(X) 1-XX)