Parent–child relationships may have a significant effect on illness characteristics of children with pediatric bipolar disorder (PBD), and these relationships may, in turn, be affected by the child's illness. We characterized maternal reports of parent–child relationships using the five-factor Parent–Child Relationship Questionnaire (PCRQ) in 60 families (30 PBD youth and 30 matched controls). Data on child proband and parental psychopathology were also obtained. Compared to controls, parent–child relationships in the PBD group were characterized by significantly less warmth, affection, and intimacy, and more quarreling and forceful punishment. Among PBD participants, elevated symptoms of mania, comorbid ADHD, an earlier age of illness onset, living in a single parent home, and the presence of a parental mood disorder were associated with greater parent–child relationship difficulties. These findings have implications for the development of interventions that focus on the quality of parent–child relationships, in addition to symptom management, in the treatment of PBD. © 2008, Wiley Periodicals, Inc. J Clin Psychol 64: 422–437, 2008.