The aim of the present study was to investigate the interplay between attention deficit hyperactivity disorder (ADHD) symptoms and emotional functioning in relation to peer problems. Parent ratings of ADHD symptoms and regulation/reactivity with regard to four emotions (anger, sadness, fear, and happiness/exuberance) at age six were investigated in relation to sociometric peer nominations 3 years later in a non‐clinical sample (n = 91). Reactivity and regulation were only modestly correlated, and these two aspects of emotional functioning did not show the same relation to peer problems. The main finding was that, it was primarily children with high levels of ADHD symptoms in combination with either high dysregulation or low reactivity with regard to happiness/exuberance who received many negative peer nominations. In addition, high levels of ADHD symptoms in combination with high reactivity with regard to anger were associated with nominations of physical aggression. The modest relation between reactivity and regulation emphasizes the importance of separating these two constructs. The fact that it was primarily happiness/exuberance, as opposed to negative emotions, that was associated with negative peer nominations suggests that future studies are needed to clarify the role of specific emotions in relation to the functional impairments associated with ADHD symptoms. Highlights The present study aimed to investigate the interplay between ADHD symptoms and emotional functioning in relation to peer problems using a longitudinal design (age 6–9 years). Ratings of ADHD symptoms and emotional functioning were investigated in relation to sociometric peer nominations and results showed that it was primarily children with high levels of ADHD symptoms in combination with either high dysregulation or low reactivity with regard to happiness/exuberance who received many negative peer nominations. The fact that it was primarily happiness/exuberance, as opposed to negative emotions, that was associated with negative peer nominations suggests that future studies are needed to clarify the role of specific emotions in relation to the functional impairments associated with ADHD symptoms.