Teachers' sense of efficacy refers to the beliefs held by teachers (pre-service and practicing) for completing the tasks associated with teaching. This belief is bound by the nature of tasks which includes, but is not limited to, the content, students, and context that frame teachers' practice. In this investigation, we explored 25 pre-service early childhood teachers' self-efficacy for teaching children with autism in inclusive settings as they participated in a course on the nature of ASD. Participants reported changes in their perceptions of ASD and of children diagnosed with ASD and they attributed their change in understanding to lessons learned from course activities. In addition, participants' self-efficacy for teaching and self-efficacy for teaching children diagnosed with ASD in inclusive settings increased over the course of the intervention.