The timing of births and marriages in Vietnam appears to have some statistically significant relationships with the signs of the Chinese and Vietnamese astrological calendars. Years considered to be good years have significantly more births and marriages than years that are not considered as desirable. Births and marriages also have some significant variations with seasons of the year. Infant deaths do not appear to have any significant relationships with the astrological signs although infant mortality has some significant relationships with seasons of the year. The findings indicate that there is some purposeful planning for marriages and births to coincide with optimal times defined in the astrological calendars.