The co-occurrence of anxiety disorders (ADs) and disruptive behavior disorders affects a substantial proportion of children and may cause significant impairment in functioning. Approximately 40% of clinic-referred youth with oppositional defiant disorder (ODD) meet criteria for an AD (Greene et al., 2002). In spite of the frequent co-occurrence of these disorders, there is little research examining the presence of AD in clinic-referred samples of youth with ODD. Thus, the purpose of the current study was to 1) examine the phenomenology of clinic-referred youth with ODD/AD as compared to youth with ODD alone, and 2) explore the role of cumulative family risk (CFR) in predicting level of impairment in youth with comorbid ODD/AD as compared to youth with ODD alone. There was mixed support for distinct clinical profiles among youth with ODD/AD as compared to youth with ODD alone: youth with ODD/AD had higher levels of anxiety, internalizing symptoms, and parent psychopathology whereas youth with ODD alone had higher levels of conduct problems, hyperactivity, and attention difficulties. However, there was little support for the role of CFR in predicting impairment in youth with ODD/AD. Future research should enlist a multi-informant, multi-contextual approach in examining the role of CFR in predicting impairment levels for youth with comorbid ODD/AD. / Ph. D.