Investigation of the adjustment of children with a chronic illness has been complicated by an imprecise definition of adjustment, immense diversity in the kinds of chronic illnesses studied, and multiple instruments and sources of measurement of the child's behavior. In this study we have used a composite construct of adjustment, looked separately at reports from three separate observers of children's behavior, and limited our investigation to a few discrete types of illnesses. The investigation explores the contribution of selected characteristics of mothers and of families to children's adjustment as reported by children, their mothers, and their teachers. Family interactions were important to the psychological adjustment of all children (healthy or with a chronic illness and independent of age and socioeconomic status) as reported by all three observers. The mother's self-esteem and reported size of her social network were not associated with children's adjustment, but the mother's health locus of control beliefs interacted with the child's intelligence to predict children's adjustment. The pattern of these associations was different for different illness groups and for each of the three observers.