In this study, similarities and differences in sibling relationships between children who have experienced family transitions and those who have not are examined. Comparisons are made between children who live in intact families, those whose parents have separated, and those who live in substitute care regarding the quality of their relationships with one of their siblings. More specifically, 4 dimensions describing the quality of sibling relationships are compared: Warmth/Closeness, Conflict, Relative Status/Power, and Rivalry (Furman & Buhrmester, 1985). The sample is made up of 3 groups of children (N = 158) aged between 8 and 12 years old: children living in intact families (n = 101), children who have experienced parental separation (n = 35), and children living in substitute care (n = 22). Results indicate differences on dimensions of Warmth/Closeness, Conflict, and Relative Status/Power. Different patterns of responses between the children who have experienced family transitions and those who have not are observed for the dimensions of Conflict and Power. The significant difference observed between the groups for the dimension of Warmth appears difficult to explain. Discussion of these results emphasizes the importance of the relationship between brothers and sisters experiencing family transition.