In-depth interviews were conducted with 14 adolescent girls (7 sister pairs) between the ages of 13 and 18 years to examine disclosure between adolescent sisters. The content of disclosures between sisters focused on relationships, particularly those with boys, family, and peers. Participants described childhood relationships as play-oriented, whereas adolescent relationships were marked by less overall interaction but more talk. They identified their sisters' ability to understand, be nonjudgmental, and be trustworthy as facilitating disclosure. The possibility that a sister may breach confidentiality through gossip or tattling, however, may limit disclosure. Participants perceived disclosure to bring them closer, to help them understand each other, and to highlight differences between them. Although disclsoure was perceived to be important, participants also valued companionship and playfulness in their relationships Perspectives and opinions of each sister within a dyad were generally congruent. Findings suggested an association between disclosure and closeness. Directions for future research are suggested