Background: Attribution theory, self-regulation, self-handicapping and sick role theories all suggest that children with chronic disease may be held to different standards. This study assesses child and parent attributions in pediatric chronic health conditions and addresses how attributional style may be related to treatment adherence. Methods: Four different vignettes were utilized to compare the attributional style of children with phenylketonuria (PKU) and parents of children with PKU to two comparison groups: children with other chronic medical conditions and medically healthy children. In addition, the relationship between metabolic control and attribution ratings was assessed in the PKU sample. Results: Parents of children with medical conditions provided attributions of less child control and more stability as well as more positive affective reactions when compared to parents of healthy children. Children without a medical condition viewed childhood problems as less controllable and more stable. Mothers were more disturbed affectively by behavioral dysregulation and fathers were more disturbed by academic difficulties. In the PKU sample, the higher the phenylalanine level in the child, the more likely the parent and child alike were to attribute childhood problems to external loci of control. Conclusions: Attributional styles appear not to be diagnosis-specific in pediatric populations. Attributional style may be an important variable to consider when targeting treatment adherence.