The goal of this study is to integrate family systems theory, reflected in the construct of coparenting, with the attachment theory's concept of mentalization and how they are linked with children's behavior problems. We investigate the direct, indirect, and moderating links between mothers' and fathers' perceived coparenting, parental mentalization, and children's externalizing and internalizing behavior in the context of parents' general anxiety. Our sample consists of 78 cohabiting, heterosexual Israeli couples and their 3- to 5-year-old children. Both parents independently completed self-report questionnaires regarding their general anxiety, coparenting experiences and children's externalizing and internalizing behavior and were individually interviewed to assess their mind-mindedness. Actor-partner interdependent model extended for mediation analysis (APIMeM) revealed a direct actor and partner effect of parents' general anxiety on perceived coparenting and on the child's externalizing and internalizing behavior, and an indirect actor effect via coparenting, in the case of the child's externalizing behavior. In all models tested, the links were similar for mothers and fathers. Regression analysis with a PROCESS macro showed that maternal mind-mindedness, but not paternal mind-mindedness, moderated the direct link between parents' general anxiety and the child's externalizing behavior. Findings demonstrate the significant impact of fathers' and mothers' anxiety on the family system and on children in particular. We discuss the importance of coparenting as an executive subsystem in the family and of maternal mentalization as a buffer against the negative impact of parents' general anxiety on the child and suggest their potential contribution for prevention and treatment interventions. (PsycInfo Database Record (c) 2021 APA, all rights reserved).