Despite growing literature in evidence-based practice (EBP) for children with autism spectrum disorder (ASD), there is limited research on best practices for training the practitioners that provide EBP. In traditional clinical psychology, training often includes self-study of intervention materials followed by ongoing supervision. Although behavioral skills training (BST) has been shown to be efficacious for training skills across many environments, it has yet to be evaluated in training clinical psychology graduate students to implement an intervention for youth with ASD. In a concurrent modified multiple baseline (multiple probe) design, we evaluated the impact of a brief (3-hr) BST session on graduate student therapists’ implementation of a cognitive–behavioral therapy intervention meant to improve emotion regulation in children with ASD. Therapists showed modest additional improvements from baseline (self-study of the intervention manuals alone) in terms of the accuracy and quality of intervention delivery after receiving BST. Additionally, all therapists preferred the BST training session to self-study and said they would recommend BST to other practitioners. Future research should evaluate what specific training components result in the most improvement in therapist behavior and what, if any, added clinical significance therapist improvement serves for clients.