Advances in the treatment of childhood malignancies have dramatically altered survival rates of children with cancer, changing the nature and scope of stressors that their families encounter. Very little is known about how childhood cancer affects healthy Chinese siblings and what can be done to help children adjust to this stressful life event. The cognitive theory of psychological stress was the framework for this study. The purpose of this research was to explore behavioral responses of healthy Chinese siblings in Taiwan to childhood cancer in the family and to examine the factors that may contribute to the presence or absence of behavioral problems in these siblings, using a 12-month longitudinal data set. Forty-five Chinese families were selected through referrals and a cancer foundation name roster. Content analysis of qualitative and quantitative sibling data revealed major stressor themes of inadequate knowledge, reduced family communication, and insufficient support. Healthy Chinese siblings showed significantly more behavior problems and fewer social competence behaviors than a standardized normal western population.