Objective: Psychological theories have postulated an association between insecure attachment and ADHD. The objective of this study is to investigate possible association between insecure attachment and ADHD in children and adults. Method: Review of literature was performed using the PsycINFO, Medline, and EMBASE databases. Results: Twenty-nine studies were included in the review. Overall, the studies showed that parental attachment problems and environmental mediating factors were significantly associated with childhood ADHD. Adults with ADHD had a much higher incidence of insecure attachment styles than reported in the general population. Conclusion: There seems to be a clear association between ADHD and insecure attachment. It is likely that early intervention in the form of parent training and pharmacological treatment may prevent development of attachment problems. But such studies have not been carried out. Furthermore, adults with ADHD might need treatment for their lack of attachment competences as well. More research on this topic is much needed. (J. of Att. Dis. 2013; XX(X) 1-XX)