This paper reports the findings of a qualitative examination of sibling relationships in old age. Interviews with sixty people over the age of sixty-five revealed that interactions with sisters and brothers took on new meaning in late life. A shared history of lifetime experiences made the sibling relationship unique in social networks in old age. Those who had positive relationships with siblings found that interactions decreased feelings of loneliness, provided emotional support and validation of earlier life experiences, and built feelings of closeness and sibling solidarity. Even those who had negative sibling relationships indicated a shift in feelings. The intensity of feeling about siblings in old age suggests that further study of the later-life sibling bond might increase understanding of ways in which the social and emotional needs of older people can be met. Interviews provided an effective method for gathering rich data about these complex social and emotional interactions.