This study examined the effects of parental hostility on the families of 100 psychiatrically hospitalized children. Parents and their children were administered an assessment battery. The results for families who scored high on parental hostility were compared to families with low parental hostility. Parents who exhibited high hostility scored differently on a variety of temperament constructs (e.g., lower adaptability, worse mood, and lower rhythmicity) than parents who scored low in hostility. High parental hostility was also associated with an elevated level of family relation problems, which includes family effectiveness and cohesion.