In this study, researchers examine the impact of ecoaching (including a web-based professional development [PD] portal consisting of a learning module, self-monitoring, and video feedback) on preschool teachers' use of a simultaneous prompting (SP) procedure and the effects of SP on teaching discrete skills to their students with autism spectrum disorder (ASD). The researchers also examine maintenance and generalization effects on teachers' and students' behaviors. Moreover, researchers investigate the social validity of the study. They use nested multiple probe designs across four preschool teacher and student dyads to evaluate the effects of the ecoaching intervention and the SP procedure, respectively, on teachers' and students' behaviors. Ecoaching was effective in the acquisition, maintenance, and generalization of preschool teachers' use of the SP procedure, and the SP procedure was effective in teaching discrete skills to students with ASD. Teachers had positive opinions about ecoaching and the SP procedure. Limitations and implications for future research are discussed.