The National Institute on Drug Abuse (NIDA) reports that six of ten individuals with a substance use disorder meet criteria for another mental illness diagnosis. These co-occurring disorders present significant challenges for both chemical dependency and mental health practitioners across levels of treatment intensity.To answer these challenges, Dialectical Behavior Therapy (DBT) has emerged as a highly teachable and applicable approach for people with complex co-morbidities. This manual outlines the acceptance-based philosophies of DBT with straight-forward guidelines for implementing them in Integrated Dual Disorder Treatment (IDDT) settings along with comprehensive explanations of DBT skills tailored for those with dual disorders.