This study examined the direct and indirect pathways from parents' work-family conflict to children's behavioral problems. Specifically, it investigated the effects of parents' work-family conflict on parental warmth, as well as the mediating roles of parental warmth and children's executive function difficulties in linking parents' work-family conflict and children's behavioral problems. Data were collected from 558 triads of dual-earner parents and their first-grade children in Korean elementary schools participating in the Panel Study on Korean Children administered by the Korea Institute of Child Care and Education. An actor-partner interdependence model and mediation analysis using structural equation modeling revealed that the actor and partner effects of parents' work-family conflict on maternal warmth were all statistically significant, whereas the actor effect of parents' work-family conflict on paternal warmth alone was significant. Furthermore, the actor effect of work-family conflict on parental warmth was greater in fathers than in mothers, whereas the partner effect of work-family conflict on parental warmth was greater in mothers than in fathers. Second, mothers' work-family conflict was directly and positively related to their children's behavioral problems, but not fathers' work-family conflict. Third, the five mediating processes were verified from parents' work-family conflict, through parental warmth and children's executive function difficulties, to their behavioral problems. Particularly, maternal warmth played a major role in most of these mediating processes. Finally, this study highlights the importance of co-parenting and children's executive function for improving the effectiveness of parent education and intervention programs for dual-income parents whose school-aged children exhibit behavioral problems.