Studies of the relation between parental cancer and psychosocial problems in teenagers regularly lack control groups, and the effects of moderator variables have hardly been investigated. The Health Study of Nord-Trøndelag County of Norway (HUNT study) 16 allowed us to examine whether a history of parental cancer moderated the associations between indicators of impaired health status of parents (adult HUNT-2 study) and psychosocial problems in their teenagers (Young-HUNT study). In this study, a history of parental cancer was treated as a family characteristic variable. On the basis of our previous study we hypothesized that such a history would have small effect on the association between impaired parental health status and psychosocial problems in their teenagers.