Though premarital sex among Thai young adults resulted in a large number of abortions and child mothers, university students were less likely than vocational students and out-of-school adolescents to have premarital sex. The authors believe that the university students’ attitude against premarital sex is fostered through mother-daughter relationships and an observance of the Buddhist five precepts. To support this contention, the authors conducted a study among 198 female university undergraduate students and hypothesized that mother-daughter relationships were related to an attitude (...) against premarital sex through the mediation effect of an observance of the five precepts. Results supported the research model, affirming the role of mother-daughter relationships in fostering an attitude against premarital sex, and suggesting that the five precepts have a protective effect in guarding against adverse health and life-changing risks among Thai adolescents. (shrink)