Transition has been described by many disciplines. However, the concept of transition has yet to be applied to the sibling experience of childhood cancer. Understanding the transitions that siblings encounter is important because it will offer nurses new possibilities for enhancing siblings' outcomes. Accordingly, the purpose of this article is to provide a conceptual framework that will assist nurses in their efforts to promote healthy transitions in siblings of children with cancer. The method of concept analysis developed by Walker and Avant [Walker, L., & Avant, K. (1995). Concept analysis. In Strategies for theory construction in nursing (3rd ed.) (pp. 37–54). Norwalk, CT: Appleton and Lane.] is employed. The result is a definition of transition that is relevant and useful for research and clinical practice in pediatric oncology.