Every year, approximately 18,000 children and adolescents are diagnosed with cancer in the United States, and many of these diagnosed children will have siblings. Some studies indicate that siblings suffer from high rates of post-traumatic stress reactions, school absenteeism, behavioral problems, and declines in academic performance. Preliminary results from “Parenting in the Face of Cancer: Non-ill Child and Parent Relationships" indicate that children have misconceptions about the cause of cancer and contagion. They are also reluctant to share their feelings and concerns with their parents, and wonder what their role is in helping their sibling with cancer. The aim of this study is to develop a children’s book to facilitate communication between parents and their non-ill children. We reviewed the published literature about the effects of cancer on school-age non-ill siblings, and conducted interviews with child life specialists who work in cancer care. We also analyzed interviews of school age (7-12 years) non-ill siblings of children with cancer. Analysis focused on sibling’s perspectives of what caused the cancer, contagion, worries and concerns, and the perceived availability of their parents. The siblings’ perspectives and misconceptions were used to develop a story that provides a simple description of cancer, addresses the siblings’ misconceptions and concerns, encourages them to share their feelings and concerns with their parents, and suggests ways they can play an active role in their sibling’s treatment. A future study will be designed to evaluate whether this interactive children’s book alone, or the book with a short nurse coaching session, will improve emotional and behavior outcomes in non-ill siblings of children with cancer.