Initial protocol development efforts will focus on adapting relevant treatment elements from an effective CBT program for younger children with ASD and comorbid anxiety to the characteristics and clinical needs of early adolescents. Thereafter, protocol and measure development will be refined during Phases I and II of this study through our experiences treating a total of 20 young adolescents (ages 11-14 years - 10 will be treated at USF; 10 at University of California, Los Angeles (UCLA)) with ASD and comorbid anxiety disorder(s). The CBT protocol will then be examined in a trial comparing CBT to a waitlist condition (N = 32 total; 16 at each study site).