The aims of the study were to estimate the prevalence of body dysmorphic symptoms in a sample of children and adolescents with obsessive-compulsive disorder, possible clinical correlates and whether BDD symptoms predict poorer treatment outcomes after cognitive behavioral therapy. The study included 269 children and adolescents with OCD, aged 7–17 years, from Denmark, Sweden, and Norway, who were treated with 14 weekly sessions of manualized, exposure-based CBT. Twenty-one patients (7.8%) had BDD symptoms. BDD symptoms were associated with older age (p = 0.003) and a higher prevalence of comorbid anxiety disorders (p = 0.025). In addition, patients with BDD symptoms endorsed a greater number of OCD symptoms than did those without BDD symptoms. Having symptoms of BDD did not affect the CBT outcome on OCD. The results of the study suggest that CBT for OCD is equally effective for those with and without comorbid BDD symptoms.