Classroom Pivotal Response Teaching (CPRT) is a naturalistic behavioral intervention for students with autism spectrum disorder (ASD) that was systematically adapted for teacher use. In this study, the authors evaluate outcomes of a large randomized trial training teachers (n = 126) to use CPRT. Training involved 12 hours of small group sessions and additional 1:1 coaching in each teacher's classroom. Overall, CPRT fidelity was significantly higher at the end of the training year relative to the observation year (B = 0.24, p = 0.001) and teachers report using CPRT an average of 47 minutes per day. Moderator analyses indicate that training, teacher, and classroom- and school-level characteristics affected CPRT fidelity. Teachers report high overall satisfaction (M = 4.37, SD = 0.45; 1-5 Likert-type scale) and confidence in their ability to use CPRT with their students (M = 4.2, SD = 0.57). In this study, the authors indicate the acceptability and feasibility of the CPRT training protocol and adds to the limited number of school-based randomized controlled trials (RCTs) evaluating interventions for students with ASD.