Within the context of a coping model, the present study attempted to determine variables associated with good and poor adjustment for siblings (N = 129) of pediatric cancer patients. Family cohesion and adaptability were found to mediate the impact of pediatric cancer on the healthy sibling. Specifically, high levels of family cohesion and adaptability were associated with better adaptation for siblings. Some support also was found for Folkman, Schaefer, and Lazarus' (1979) coping model, as the following variables, proposed by the model, predicted sibling adjustment to pediatric cancer: health/energy/morale, social support, and utilitarian resources. Results from this study stress the need to examine the child in a variety of ecological contexts (e.g., parental and familial functioning; neighborhood/community support).