This paper focuses on the aspects of a qualitative research project that examines an assessment protocol for the placement of siblings in foster care and/or future adoption. A brief description of the background to the study and the research design is given. Evaluating the material from the quantitative instruments used and the psychotherapeutic assessments, the author identified two predominant themes. The first, cumulative trauma, pointed to the pervasive nature of the children's early experiences, as manifest through their presentation and play. The second, relatedness and belonging, highlighted aspects of the children's shared memories and experiences. Clinical vignettes are used to illustrate the way in which these themes related to the children's sibling relationships. The author reflects on the methodology used that allowed the complexity of the issues being studied to 'come to life'. The study noted the tendency for those caring for or working with the children to underestimate the children's meaning to each other and emphasised the importance of assessing the children's perspectives where decisions are being made in childcare cases. Further questions were raised as to whether more could be done to mediate or facilitate sibling relationships for children who have suffered early deprivation or abuse, and the need for further research into this area of work was proposed.Keywords Sibling relationships; foster care; assessment; psychotherapeutic research.The relationship between young siblings is distinctive in its emotional power and intimacy, its qualities of competitiveness, ambivalence, and of emotional understanding that can be used to provoke or support. On common sense grounds these qualities, and the high frequency of interaction and imitation between siblings, suggests that the relationship will be of developmental importance -both through the direct impact of siblings upon one another, and through the indirect effects of the siblings' relationships with the parents.