Children with Attention Deficit/Hyperactivity Disorder (ADHD) often have poor peer relationships, as evidenced by difficulties in being accepted and befriended by peers, as well as poor quality and stability in any friendships they do have. This peer impairment is important for researchers and clinicians to consider because it can exacerbate behavior problems, emotional maladjustment, and academic failure over time in children with ADHD. In this review, we highlight the important ways in which children with ADHD demonstrate impairment in their peer relationships. We argue that the traditional conceptualization of peer problems, which focuses on inappropriate behaviors within children with ADHD to explain their social difficulties, fails to take into account peer group factors that also contribute to the peer impairment seen in ADHD populations. Further, the predominant focus on changing the behavior deficits of children with ADHD has limited the design of effective treatments that address the multifaceted reasons for peer impairment in this population. We conclude with a discussion of implications and future directions for clinical intervention and research.