Adolescents with high-functioning autism spectrum disorders (ASDs) are at high risk for developing psychiatric symptoms, with anxiety disorders among the most commonly cooccurring. Cognitive behavior therapies (CBTs) are considered the best practice for treating anxiety in the general population. Modified CBT approaches for youth with high-functioning ASD and anxiety have resulted in significant reductions in anxiety following intervention. The purpose of the present study was to develop an intervention for treating anxiety in adolescents with ASD based on a CBT program designed for school-aged children. The Facing Your Fears-Adolescent Version (FYF-A) program was developed; feasibility and acceptability data were obtained, along with initial efficacy of the intervention. Twenty-four adolescents, aged 13–18, completed the FYF-A intervention. Results indicated significant reductions in anxiety severity and interference posttreatment, with low rates of anxiety maintained at 3-month follow-up. In addition, nearly 46% of teen participants met criteria for a positive treatment response on primary diagnosis following the intervention. Initial findings from the current study are encouraging and suggest that modified group CBT for adolescents with high-functioning ASD may be effective in reducing anxiety symptoms. Limitations include small sample size and lack of control group. Future directions are discussed.