This study examines the impact of several of the most common comorbid psychiatric disorders (i.e., generalized anxiety disorder (GAD); major depressive disorder (MDD); social phobia, and panic disorder) on cognitive-behavioral therapy (CBT) response in adults with obsessive-compulsive disorder (OCD). One hundred and forty-three adults with OCD (range = 18-79 years) received 14 sessions of weekly or intensive CBT. Assessments were conducted before and after treatment. Primary outcomes included scores on the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), response rates, and remission status. Sixty-nine percent of participants met criteria for at least one comorbid diagnosis. Although baseline OCD severity was slightly higher among individuals with OCD + MDD and OCD + GAD (in comparison to those with OCD-only), neither the presence nor the number of pre-treatment comorbid disorders predicated symptom severity, treatment response, remission, or clinically significant change rates at post-treatment. These data suggest that CBT for OCD is robust to the presence of certain common Axis-I comorbidities.