Attention-deficit/hyperactivity disorder (ADHD) is a complex, and multifactorial and chronic neurodevelopmental disorder. Comorbid psychiatric disorders are highly prevalent in individuals with a diagnosis of ADHD. There is a solid overlap between ADHD and substance use disorders (SUD). Prevalence of SUD is high among patients with ADHD, so that SUD are approximately double as common among individuals with ADHD than in general population, and individuals with SUD have much higher rates than expected of a comorbid ADHD. Studies shown that treatment during childhood of attention-deficit/hyperactivity disorder with stimulant medication neither protects nor increases the risk of later substance use disorders. Nevertheless, recent studies found that patients with ADHD and SUD can reduce ADHD symptoms and SUD with stimulants and cognitive-behavioral therapy. Treatment of ADHD in patients with SUD requires a comprehensive diagnostic assessment. It is recommendable to stabilize the addiction prior to treating the ADHD. In this talk, the recent literature for the treatment of adults with co-occurring ADHD and SUD will be reviewed.