Following the important insight that what parents know about their adolescent offspring depends primarily on what the child tells them, this study examines how attitudes about what parents have a right to know mediate the associations between several factors (quality of parent-child relationships, time spent with family and peers, levels of antisocial and prosocial behaviors, and gender and age) and adolescents' disclosures about peer relations. In two studies of early and middle adolescents (Ns = 231, 249; M ages = 14.5, 13.0; 62.3, 51.8 % female; 53.7, 67.5 % European American), a new measure of right-to-know attitudes is derived and then applied to four facets of adolescents' experiences with peers: details of activities with peers, issues in specific relationships, and positive and negative peer characteristics. The findings indicate that adolescents are more inclined to disclose certain aspects of their peer relations than others, but these inclinations are related to several factors-especially the quality of mother-child relationships and involvement in antisocial behavior-and mediated by adolescents' attitudes regarding what parents have a right to know about peers. The results are related to autonomy development and parental oversight of adolescent peer interactions.