This is one of six titles resulting from the Ethnicity and Fertility in Southeast Asia Project that commenced in 1980. Building upon the results of an earlier study, which established that ethnicity was a significant factor underlying the fertility differentials among the various ethnic groups in Southeast Asia, the project aimed to explore in greater detail the extent to which ethnicity and ethnic factors such as ethnic attitudes, ethnic identification and cultural practices influenced reproductive behaviour. Instead of utilizing secondary sources, the project relied on primary data collected through the survey technique. In all, twenty ethnic groups from the five ASEAN countries were surveyed in this study which spanned a period of three years.