This study aims to enhance understanding of mother-daughter communication about dating and romantic relationships. We explored how Mexican-origin, mostly immigrant mothers talked about these topics with their daughters (ages 13 to 16 years) using videotaped observational methods. Themes drawn from the maternal messages contained in the conversations of 132 mother-daughter dyads show that mothers promote positive decision-making among their daughters, advising them to take their time, choose partners wisely, insist on respect from boys, maintain autonomy in relationships, pursue education goals, and develop a sense of self-worth. Mothers expressed concern about their daughters being pressured or manipulated into having unwanted sex, which led to messages about negative partner dynamics predominating in conversations. Communication about risks, however, included only implicit advice about self-protective behaviours and few messages about the potential for dating violence and abuse. We discuss the implications for improving the design of sexual health communication programmes in which mothers and daughters jointly participate.