Background: The high prevalence of attention problems in children warrants concern, as it is a risk factor for internalizing and externalizing problems. There lies a need to understand possible factors that may mediate this link so that interventions may be targeted to alleviate these mediators and interrupt the link between attention problems and negative outcomes. Objective: This study investigated the role of peer problems in the association between attention problems and internalizing problems, and between attention problems and externalizing problems in an Asian sample (N = 312). Method: Participants' data were from the archival records of an outpatient child psychiatric clinic. Results: Findings indicated that peer problems was a statistically significant mediator for both associations. Additionally, peer problems was a complete mediator for the association between attention problems and internalizing problems, but a partial mediator for the link between attention problems and externalizing problems. Conclusions: Findings suggest that the association between attention problems and internalizing and externalizing problems occurs via an indirect mediated pathway, through peer problems. These findings provide some preliminary evidence for the design and evaluation of future intervention studies aimed at the peer group level for the amelioration of peer problems in children with attention problems.