Given the high rates of comorbid anxiety and autism spectrum disorder (ASD) in the adolescent and young adult population, effective treatment protocols to address anxiety symptoms are of importance to help promote greater independence across settings. While research supports the use of cognitive-behavioral therapy (CBT) across younger age groups with ASD, the literature is limited on interventions benefitting adolescents and young adults with comorbid anxiety disorders and ASD. Therefore, this open trial utilized a modified CBT manual for seven participants between the ages of 16 and 20 years, consisting of a 16-week modularized CBT treatment, including psychoeducation, cognitive therapy, and exposure therapy. Measures of anxiety and depression were completed at baseline and post-treatment. Findings demonstrated significant reductions on clinician-rated measures of anxiety. While findings are encouraging, additional studies examining the efficacy of CBT for this population with ASD and clinical anxiety are necessary to further identify beneficial treatment components.