This research study was designed to investigate the relationships of stress, anxiety, self concept, social support and illness in children and to examine the potential of specific cognitive mediating variables, self concept and anxiety, and an external mediating variable, social support and an interaction between self concept and social support, to significantly increase the efficiency of stress as a predictor of children's illness. The purposes of this study were (1) to determine if stressful life events, anxiety, self concept, social support, sex and illness are related in children, (2) to determine if stressful life events are an adequate predictor of illness in children, (3) to determine if a combination of anxiety, self concept and social support will increase the predictive efficiency concerning illness in children, (4) to provide information that may help develop a theoretical base concerning stressful life events and illness in children, and (5) to provide information that may be beneficial with regard to future research involving stress, anxiety, self concept, social support, sex and illness in children.