Objective: Few guidelines are available regarding optimal training models for practitioners delivering cognitive-behavioral therapy (CBT) for anxiety in youth with autism spectrum disorder (ASD). The present study systematically compared 3 instructional conditions for delivering the Facing Your Fears program (FYF) to children with ASD and anxiety. Method: Thirty-four clinicians (Mage = 34 years; 94% women, 88% Caucasian) and an intent-to-treat sample of 91 children with ASD and anxiety (Mage = 11; 84% male 53% Caucasian) met eligibility criteria across 4 sites. A 3-group parallel design via a Latin square procedure was used to randomize 9 teams of clinicians to 1 of 3 training conditions: Manual, Workshop, Workshop-Plus. The effectiveness of instructional condition was assessed via implementation (CBT knowledge, treatment fidelity) and treatment outcomes (reductions in anxiety as measured by the Anxiety Disorders Interview Schedule-Parent (ADIS-P). Results: Clinicians in both Workshop conditions significantly increased CBT knowledge postworkshop, F(1, 18) = 19.8, p <.001. Excellent treatment fidelity was obtained across conditions (above 89%), although clinicians in the Workshop conditions obtained significantly higher fidelity ratings and delivered FYF with greater quality than the Manual condition. Children with ASD demonstrated significant reductions in anxiety symptoms for three of the four anxiety diagnoses, with no differences noted across instructional condition. Rates of improvement were lower than those obtained in a previous controlled trial. Conclusions: Results suggest that although there may be some advantage to participating in a Workshop, clinicians in all conditions could deliver FYF with excellent fidelity and yield positive treatment outcomes. Lack of a no-treatment comparison group limits interpretation of findings.