This study aims to identify the relationship between the degree of uncertainty in the preadolescent's chronic condition and family distress. In-home interviews were conducted with 99 mothers and 86 fathers of 99 preadolescents with chronic physical health impairments. Preadolescents were divided into separate groups, first based on the predictability of their symptoms and next, based on the degree of certainty in their life expectancy. Using analysis of covariance, sex-stratified comparisons were made between the predictability groups and then between the life expectancy groups and four subscales of the Impact on Family Scale. Fathers and mothers of preadolescents with uncertain life expectancies reported significantly greater family/social disruption, emotional strain, and financial burden than parents of preadolescents with normal life expectancies. Unpredictability of symptoms was significantly associated with greater emotional strain for mothers and greater family/social disruption for fathers. Uncertain life expectancy and unpredictable symptoms were associated with significantly more family distress.