This study aims to examine the impact of parental international migration on the mental health of children left behind. Data for this paper were taken from the ‘Child Health and Migrant Parents in South-East Asia, Thailand, 2008’ project. A total of 1,030 children (519 from emigrant parents and 511 from non-migrant parents) were covered. Data were collected from the caregivers of children using the Strength and Difficulties Questionnaire. Multivariate analyses were performed to determine the association between parental migration and the mental health status of children left behind. Several factors were significantly associated with children’s mental health. Our study did not find any association between current parental migration status and mental health status of the children left behind. The study found, however, that mother’s earlier migration history had a significant, independent association with mental health problems of the children left behind. Therefore, effective strategies to prevent such mental health problems among children are warranted.