Worryingly low levels of parent–child agreement on child psychiatric diagnosis are reported. This study examined parent–child agreement on diagnostic categories and severity ratings with the Anxiety Disorders Interview Schedule, Child and Parents versions (ADIS-C/P). Children’s age, gender, motivation and self-concept and parent’s general psychopathology and diagnoses were examined. Participants were 110 children (aged 8–14 years) with a principal specific phobia diagnosis, and their parents. Findings revealed excellent parent–child agreement on principal specific phobia diagnosis (97.3%), and fair levels of concordance on most co-occurring secondary diagnoses. As expected, children with high motivation had generally stronger parent–child agreement on diagnoses and severity ratings (for ADHD p < .001). Parents reported overall more diagnoses for their children (for GAD p < .03; SOCP p < .02) and parents with diagnoses seemed more tuned in to their children’s problematic behavior. It is suggested that clinicians screen for motivation status early in the assessment phase and use both parts of the ADIS-C/P.