Children with attention-deficit/hyperactivity disorder (ADHD) often struggle with emotion regulation deficits. While much research explored the neurodevelopmental antecedents of emotion dysregulation in ADHD, little is known about how parents can help regulate children with ADHD in daily life. In this study, we examined parental interpersonal emotion regulation (IER) strategies during a conflict discussion with their child and their impact on the child's emotion dysregulation during the interaction. Fifty-eight two-parent mother and father Israeli families of children diagnosed with ADHD ( = 9.37, 70% males) completed diagnostic assessment and symptom severity questionnaires and participated in a triadic conflict discussion. Parental IER strategies were coded into nonsupportive, emotion-focused, and solution-focused strategies. The child's emotion dysregulation was evaluated before the conflict discussion using the Child Behavior Checklist Dysregulation profile and during the conflict discussion using pitch analysis of the child's vocal response. Results indicated that mothers made more IER attempts than fathers. Emotion- and solution-focused strategies significantly contributed to children's reduced emotion dysregulation during the interaction. Parental supportive IER strategies moderated the relationship between the child's reported and momentary emotion dysregulation. The results emphasize the significance of both paternal and maternal IER for children with ADHD, highlighting the imperative to incorporate parental IER strategies in interventions aimed at supporting children with ADHD. (PsycInfo Database Record (c) 2025 APA, all rights reserved).