The sex ratio at birth (SRB) is defined as the number of male children being born per 100 females. The biologically normal SRB lies between 102 and 106. In Viet Nam, the SRB was still at the biologically normal level in the year 2000, but rose to 110.5 by 2009 and to 112.2 by 2016. In some provinces, this figure was as high as 117 male children per 100 female children. This policy brief presents new information on the skewed SRB in Viet Nam and its socio-cultural context, offering an analysis of recent demographic developments and research-based recommendations for ways forward.