Abstract Children's knowledge of their illness and the possibility of dying from their disease were evaluated in 90 families of pediatric cancer patients 2 months after diagnosis. Maternal protective parenting, affective distress, coping style, and knowledge about the child's illness were evaluated as predictors of illness and prognosis information disclosure. Information disclosure was expected to predict child affective distress. As expected, children who knew they had cancer or simply knew that they were sick had fewer maternal-reported internalizing behaviors than children with minimal knowledge of their illness. No significant difference was found between children with knowledge of cancer and knowledge of being sick. Maternal depression and approach coping style predicted child knowledge of illness and possibility of death, respectively, in elementary-school aged children (6-10-years-old). Mothers' confusion about their child's illness, prognosis,and treatment, predicted less child knowledge of illness, for elementary and middle/high school aged children (6-18-years-old) and knowledge of the possibility of death for elementary school aged children. Results suggest that providing children with meaningful information regarding their illness rather than withholding illness information may help lessen their affective distress. Specific information about the illness as cancer may not provide additional benefit for children with respect to affective distress beyond that provided by the knowledge that they are sick. Mothers may benefit from greater education about their child's illness and more support to manage their depression to facilitate open parent-child communication about the illness and its prognosis and help lessen child affective distress.