Objectives: This study aimed to explore the variables predicting school readiness in young children from multicultural families in terms of immigrant mothers' beliefs about their children starting school, South Korean fathers' parenting participation, and mother-teacher partnerships. Methods: The participants were 116 mother-child pairs from the 25 preschools in Seoul, Gyeonggi, and South Chungcheong provinces where multicultural families are concentrated. Results: Some background variables, such as children's gender, duration of attending preschool, and mothers' Korean language ability, were associated with the children's school readiness. Mothers' beliefs about their children starting school, fathers' parenting participation, and mother-teacher partnerships had a significant effect on school readiness significantly. Conclusion: Over and above these findings, the authors emphasize the importance of parents' and teachers' individual roles, as well as the interactions between them, in improving multicultural children's school readiness.