This multi-method study provides detailed information about the friendships of 87 children with ADHD (77.0% boys) and 46 comparison children (73.9% boys) between the ages of 7 and 13.The methods used in the study included parent and teacher ratings, self-report measures, and direct observation of friends' dyadic behaviours in three structured analogue tasks. Results indicated that, in contrast with comparison children, children with ADHD had friends with high levels of ADHD and oppositional symptoms; they perceived fewer positive features and more negative features, and were less satisfied in their friendships. Observational data indicated that children with ADHD performed both more legal and more illegal manoeuvres than comparison children in a fast-paced competitive game. While negotiating with their friends, children with ADHD made more insensitive and self-centred proposals than comparison children. In dyads consisting of one child with ADHD and one typically developing child, children with ADHD were often more controlling than their non-diagnosed friends. Globally, these results were robust and did not seem to be affected by age differences, ADHD subtypes, comorbidities, and medication status. Given the increased recognition of ADHD in adolescence and adulthood as well as the fact that negative peer reputation in childhood very strongly predicts mental-health status by early adulthood, this research may lead to the discovery of meaningful ways to help people with ADHD achieve improved mental health and happiness over their lifespan.Friendship Interactions of Children with ADHD 1