OBJECTIVE: Attention-Deficit/Hyperactivity Disorder (ADHD) is one of the most prevalent childhood disorders, affecting around 3.4% of children worldwide. A common and impairing correlate of ADHD is aggressive behaviour. ADHD symptoms and aggression are both heterogeneous and it has been speculated that certain symptoms of ADHD might be more important in aggressive behaviours of different types than others. This study uses a symptom-level analysis to investigate the concurrent and temporal links between ADHD symptoms and aggressive behaviours. METHODS: Using Gaussian Graphical Models and Graphical Vector Autoregression Models, longitudinal and cross-sectional networks of ADHD symptoms and aggressive behaviours, measured using parent-reported Social Behaviour Questionnaires, were estimated. Participants included 1,246 children taking part in the longitudinal Swiss z-proso cohort study at ages 7, 9 and 11. RESULTS: The longitudinal network highlighted that ADHD symptoms and aggressive behaviours share a multitude of reciprocal temporal relations, with inattentive ADHD symptoms preceding both reactive and proactive aggression. Cross-sectional networks suggested that hyperactive/impulsive symptoms were predominantly connected to reactive aggressive behaviours but also to a form of proactive aggression, namely dominating other children. CONCLUSION: Findings provide preliminary evidence which specific symptoms are the most promising targets for reducing aggressive behaviours in children with ADHD. They also highlight the potential importance of targeting feedback loops resulting from aggressive behaviours. Future research is needed to better understand the mechanisms through which ADHD and aggressive behaviours become linked.