An imbalance of the Sex Ratio at Birth (SRB) in Vietnam has emerged since the early 2000s. The number of males born compared to females has reached unstable levels reflecting a discrimination against girls that threatens the country’s population with negative consequences. South Korea is the only country that has experienced skewed SRB and has been able to reverse its national levels back to stability. There is a lack of material in the literature of a direct comparison of Vietnam and South Korea. This paper reviews existing articles on the contributing factors of SRB that include primarily son preference, prenatal sex selective practices and low fertility. It also aims to assess South Korea’s approaches in solving its SRB crisis in order to inform recommendations to improve Vietnam’s strategy to combat this health problem. Quantitative studies in the literature reveal the magnitude of the problem. There is a lesser amount of qualitative research that sheds light on the underlying reasons of unusual SRB that is rooted in patriarchal kinship systems, which fuels son preference. South Korea’s political will, acceptability of a bilateral kinship system and normative changes on how children are viewed serves as an example of how Vietnam can return to appropriate SRB levels.