In this master thesis, the main subject is about the relevance of sibling relations in foster care. The primary focus of this thesis is located on the subjective viewpoint of siblings, who are placed in foster homes together as well as their foster parents. In this thesis it has been investigated which factors support or inhibit the integration of siblings into the foster family. Furthermore potentials and problems of cohabitation will be examined to show how they could affect the childrens behaviour. In order to answer the main question of this research study, the internal method of triangulation inside the qualitative research was used which includes guided problem-centered interviews, narrative interviews as well as the analysis of drawings from the foster children. The representation of the single results takes place through the presentation of family cases, which got combined afterwards. The essential result of this master thesis shows, that all interviewed siblings turned out to be helpful for the process of integration.