The relationships between siblings in old age have not received much attention in social science literature. However, some researchers suggest that a reawakening of interest in and contact with siblings occurs for many people during the last part of life. Different kinds of sibling relationships that exist between older people and the ways in which each type meets or ignores the social and psychological needs of older people were examined in this study. Five types of sibling relationships emerged from data collected in open-ended interviews with 30 men and 30 women over the age of 65 who had at least one living sibling. The relationship types included Intimate (17%), the Congenial (28%), the Loyal (35%), the Apathetic (10%), and the Hostile (10%). Each type reflects a discrete pattern of instrumental support, emotional support, and contact as well as a different degree of closeness, envy, resentment, approval, and involvement with the sibling. The distribution of same-sex and cross-sex dyads among the types suggests gender differences in sibling interactions. According to the responses of the participants in this study, although the sex of the respondent did not significantly affect the position of the dyad in typology, the gender composition of the dyad did. Examining sibling relations across the life span would increase our understanding of the social and cultural contexts in which life-long sibling loyalties are fostered. Tables and a three-page reference list are provided. (Author/ABL)