Children, who grow up in families, where their parents have decided to take care of a foster child on a commission of the social welfare services, are not often given the possibility to tell about their experience of having foster siblings, in research and other studies. The aim of this study was to give biological children, in these families, a chance to tell their narratives of growing up with foster siblings, creating opportunities for families, who might have plans to take care of foster children in the future. They can get a picture of how it could be for the family´s own children. The biological children got the opportunity to tell their narrative stories including the relationships in their families and how they were looking forward into their own future and family life. The used theory takes part in systemic thinking, looking at the family as an organization and how identities are created in relationships and in communication. The method was interviews with six “children” and analyze of the text material. The result is presented in short summaries and quotation. The result shows that the children have been influenced in different ways by living with foster siblings and they have a large empathize for their parents and the situation. It also shows that the relations between the biological children and the foster children can be lasting for their future and the biological children can see the foster child as a “real” sibling. Communication and the feeling of participation were important for the children. All stories are individual but some conclusions appear. One is that the children is involved in everything that happens around them and they have own strategies to handle it.