Background <p>Recent findings suggest that family environmental factors contribute to obsessive compulsive disorder (OCD) symptom maintenance for young people and are also context dependent. Targeting these factors in family-based interventions is increasingly warranted.</p> Objective <p>This study examined family factors associated with pediatric OCD in the novel context of an anxiety-provoking situation, and in response to family-based cognitive behavior therapy (FCBT). We aimed to (1) identify parent and child behaviors distinguishing families of young people with OCD from non-clinical controls during a speech preparation task, and (2) evaluate changes in these behaviors following FCBT, with a focus on associations with OCD symptom improvement.</p> Methods <p>Participants were 38 children and adolescents and their parents, assigned to OCD or non-clinical control groups. Groups were compared on observer-rated child and parent behavioral dimensions. Observed parent and child behaviors were also compared pre- and post-treatment for OCD group participants completing FCBT.</p> Results <p>OCD families could be distinguished from control families on negative interaction patterns in response to the stressor task, primarily for parents. OCD group parents demonstrated more overinvolvement, task responsibility, reassurance providing, and doubt, and less autonomy granting and confidence in their child, compared to controls. Young people with OCD showed more reassurance-seeking behavior compared to controls, which significantly improved after treatment, along with corresponding reductions in parental reassurance. Notably, decreases in parental overinvolvement were significantly correlated with reductions in OCD symptom severity pre- to post-treatment.</p> Conclusions <p>Findings support integrating family factors into OCD models and targeting these factors in evidence-based treatment.</p>