Attention deficit hyperactivity disorder (ADHD) is a neurobehavioral, developmental disorder most often diagnosed during childhood, marked by the core symptoms of inattention, hyperactivity, and impulsivity that results in social, academic, and occupational underachievement. Although the disorder has a prevalence of 3-9% in the general childhood population and 1-5% in the general adult population, it affects between 11 and 35% of "substance-abusing" adults, oftentimes complicating treatment response. The present review discusses diagnostic assessment issues, prevalence, comorbidity, pharmacotherapy, and psychological interventions in substance-abusing adults with ADHD.