Many clients with mild to borderline intellectual disability (ID) who are admitted to a treatment facility show serious problems in alcohol and/or drugs use. In the present case file study, we explored differences in coping strategies, adaptive skills and emotional and behavioral problems between clients who showed substance abuse and clients who did not. There were no differences in adaptive skills between groups. However, compared to clients without substance abuse, those who abused substances showed a more palliative coping style, and had more severe emotional and behavior problems such as anxiety/depression and intrusive thoughts and aggressive and antisocial behaviors. Implications for treatment are discussed.