The authors examined how the structure of mother-adolescent conversations differs by ethnic group, age, and dyadic and individual factors. Mother-adolescent dyads of European or Latino descent participated in conversations and reported on their relationship and AIDS knowledge. Latina American mothers dominated conversations more than European American mothers, independent of socioeconomic status. Mothers dominated conversations about sexuality and AIDS more than conversations about conflicts. Mothers of older adolescents reacted more negatively, and older adolescents reported less satisfaction, less openness, and more sexual discussions with persons other than their mothers. Latino American adolescents whose mothers dominated conversations more reported fewer sexual discussions. Latina American mothers who dominated conversations more reported more openness and satisfaction. When mothers dominated conversations more, adolescents had lower AIDS knowledge.