The normative basis of marriage timing in Thailand was explored using focus group sessions as a way of obtaining qualitative information about attitudes and beliefs concerning the appropriate age at 1st marriage for men and women. A focus group session consists of a group discussion in which a small number of participants (usually 6-9) under the guidance of a moderator talk about topics of importance to the particular research study. The informal group situation is intended to encourage participants to elaborate on behavior and opinions to a greater extent than might be forthcoming from more formalized individual interview situations. Given the main objective of exploring the recent transformation of reproductive behavior in Thailand the project was designed to facilitate a comparison between the pre and post fertility decline generations. The pretransition generation was defined as married persons who had experienced most or all of their childbearing prior to the rapid changes in reproductive behavior that took place over the last decade and who had at least 5 living children. The post transition generation was defined as young married persons in their 20s for women and in their 20s or early 30s for men who wanted to have 2 or 3 children. Separate sessions were held for older men older women younger men and younger women. Complete sets of 4 sessions were held in 1 village each in the Central North and Northeastern Regions and in both a Buddhist and a Moslem village in the South. All but an older generation mens session have been held among construction workers in Bangkok all of whom migrated from rural areas. The findings draw on material from all 23 sessions. The discussions indicated that there was a reasonably clear consensus that a woman should marry in his mid 20s with 25 being most commonly mentioned. in general the recommended ages at marriage resemble the distribution of acutal ages at which men and women marry in Thailand and the mean of the recommended ages is fairly close to the actual average age at 1st marriage. During all the focus group sessions only once was the issue of brideprice payments raised and there seemed to be no acknowledged relationship between brideprice payments and appropriate age at marriage for men or women. There also was no link made between the onset of menarche and age at marriage for women and no concern expressed about a delay of marriage increasing the danger of a woman having her virginity compromised. There likewise was no advocacy that a woman should marry early in order to maximize her reproductive potential. The findings suggest that the link between age at marriage and family size is largely unintentional and that decisions as to when to marry are not viewed as a way to deliberately control family size.