Parental care in China is traditionally provided by sons. In recent decades – partly due to the One-Child Policy but also economic development and urbanisation – significant changes have occurred with parents receiving more care from daughters. Our study compares the mental wellbeing of parents who receive eldercare from daughters and sons in China, analysing the harmonised 2013, 2015 and 2018 waves of CHARLS with random-effects logistic estimates. Mental wellbeing is measured with the 10-item Center for Epidemiological Studies-Depression (CES-D-10). We find that older parents have better mental health if their primary carers are sons compared with daughters and others. This difference mainly exists among rural areas, women, and parents with limited resources. The One-Child Policy was more effective in urban areas, reducing both the availability of sons and cultural son preference. Higher levels of education received by girls in urban settings increase their employability and thus their ability to materially care for their parents. However, traditional norms and gender differences in socioeconomic statuses still persist in rural areas, leading to higher mental health from those cared for by sons, especially amongst those heavily dependent on their children — mothers or parents with less wealth. This has implications for care in rural areas as the one-child policy will impact upon gendered care for many decades to come.