One-child transnational families are the product of the "one-child" policy, access to foreign travel, and the rise of a middle class that could afford overseas education for the only child. One result was the possibility of the only child, following its Western-based education, settling (semi)permanently in the host country. This situation raises the issue of how the only child balances the opportunities in the West with the filial responsibilities to ageing parents back in China. Recognising the diversity of family forms, this study highlights the "human story" of ageing and intergenerational relations in families split between China and the UK. Drawing on 40 interviews, which included one-child migrants in the UK and some of their parents in China, this article explores the views of both generations. The findings indicate that international migration and increased family affluence did not lead to the erosion of filial piety. However, the practice and perception of filial piety among these families underwent a complex transition. Distance and borders posed future significant barriers for parental long-term care. One-child migrants tended to compensate for the lack of material/practical care by providing long-distance emotional care for their parents. Both generations expressed ambivalence towards this new transnational family contract. Instead of focusing on the practical outcomes, this article argues for the importance of examining how the members of transnational families perceive their filial behaviour. This focus brings out the less visible changing dynamics of intergenerational care in the context of modernisation and globalisation.