This study examined whether coparenting during toddlerhood predicts children’s later symptoms of attention deficit/hyperactivity disorder, oppositional defiant disorder, affective disorder, and somatic complaints. When children were 2 years old, 108 middle-class nonclinical families were observed in triadic interactions to assess two domains of dyadic coparenting (competitive and cooperative), as well as each parent’s individual competitive behavior toward the spouse. Teachers and mothers reported children’s symptoms of psychological problems at age 7. Independent of cooperative coparenting and each parents’ individual harsh parenting, competitive coparenting predicted children’s symptoms of ADHD and ODD. Interactions with child gender indicated that competitive coparenting predicted ADHD symptoms in boys (not in girls) and teacher-reported (not mother-reported) somatic complaints in girls (not in boys). ODD and ADHD symptoms were also predicted by fathers’ (not mothers’) individual competitive behaviors. The children of parents who were both low in competitive behaviors had the lowest teacher-rated symptoms of affective disorder.