2 studies were conducted to illustrate how measuring a specific aspect of marriage, namely, child-rearing disagreements, provides a better understanding of the link between marriage and boys' behavior. In Study 1, 200 mothers of 3-year-old boys completed unstandardized measures of marital functioning and child behavior. An index of child-rearing disagreements: (1) correlated with a greater variety of behavior problems than nonchild disagreements, and (2) improved upon the prediction of behavior problems after accounting for nonchild disagreements as well as after accounting for boys' exposure to marital conflict. In Study 2, 87 mothers with 4-6-year-old sons completed the index of child-rearing disagreements used in Study 1 as well as standard measures of marital functioning and child behavior. Child-rearing disagreements: (1) predicted a greater variety of behavior problems than global marital adjustment, and (2) improved upon the prediction of internalizing problems after controlling for global marital adjustment as well as after controlling for boys' exposure to marital conflict.