The brief emphasizes that son preference and the practice of sex selection in Viet Nam lie behind the skewed sex ratio at birth, and that both are deeply rooted in the male-oriented kinship system in Viet Nam.To address the issues that are at the root of the skewed sex ratio at birth, critical reflection on the country’s cultural traditions in the domain of family and childbearing is needed. Furthermore, health providers’ illegal provision of fetal sex determination and sex selection must also be addressed.