Purpose: This study investigated the current mental health status of school-age children from multicultural families and explored the maternal factors influencing their mental health. Methods: The subjects consisted of 70 pairs of elementary students and their mothers who were registered at Global Children Center in A City and Support Center for Multicultural Families in H County. One of the dependent variables was the children`s mental health measured using the Korea Child Behavior Checklist, and the predictors were the maternal factors measured using the Korean General Health Questionnaire, modified East Asian Acculturation Measure, modified Acculturation Stress Scale for International Students, and reformulated Social Support Scale. Results: 14.7% of the children were within the clinical range for total social competence, and 8.7% showed elevated total behavior problems. Maternal acculturation stress, marginalization, and depression were the predictors of the total social competence, explaining 25.0% of the latter. One of the contributors to the total behavior problems was the maternal mental health, explaining 18.0% of such. Conclusion: The findings indicated that promoting the mental health of children from multicultural families requires comprehensive support for positive acculturation and the promotion of mental health in interracial married women.