Studies on international marriage examining the motives in women’s marriage and migration decisions have indicated the limitations of the distinction between categories of migrants for marriage and migrant workers. Gender ideologies and immigration policies have accounted for women’s diverse motivations of transnational marriage; however, studies have focused on women in their first marriage, leaving those of remarried women, whose marital and migration decisions are often linked to the welfare and life trajectories of their children underexamined. Systematic investigations of institutional factors other than immigration policies in both receiving and sending countries, particularly post-Socialist societies, that affect their marital and migration decisions, remain limited. This article highlights the significance of life course, families, and gendered institutions in understanding the migratory flows of remarried immigrant wives. Based on in-depth interviews with remarried Mainland Chinese women in Hong Kong, the study argues that the effects of the labour market, local patriarchy, kinship system, and migration control mechanisms in post-Socialist China and Hong Kong on their remarital decisions vary depending on women’s life courses. Their decisions are embedded in their most salient family relationships, particularly young and adolescent biological children, which are interconnected within specific socio-historical contexts. The study contributes to research on gender and migration by demonstrating the heterogeneity of marriage migrants who are not merely wives or workers but also mothers of diverse life courses and the differential effects of gendered institutions on their remarital and migration decisions. Copyright © 2019 The Author(s). Published by Oxford University Press. All rights reserved.