Over a quarter of children with Attention-deficit/hyperactivity disorder (ADHD) meet diagnostic criteria for an anxiety disorder as well. The goals of this paper are (a) to examine what is currently known about co-occurring ADHD and anxiety in children, (b) propose and outline underlying factors relevant to the development of anxiety in children with ADHD, and (c) discuss future directions and clinical implications for the prevention and identification of anxiety development in children with ADHD. It is proposed that certain associated features of ADHD (i.e., low effortful control and emotion dysregulation) as well as various interpersonal factors related to ADHD (i.e., poor parent, teacher, and peer relationships) form a negative feedback loop that increases susceptibility to anxiety in a subset of children with ADHD. The literature supports interrelations between and across the associated features and interpersonal factors. Additional research is needed to test the validity of the proposed process. Obtaining further insight into the interplay between these different factors can help identify a subset of children with ADHD who are at risk for developing anxiety, which can enhance the precision of prevention, assessment, and treatment efforts for these children.