Problem Statement. The increased prevalence of children identified with Autism Spectrum Disorders (ASD) will likely result in these students being placed more frequently in general education classrooms. As a result, general education teachers will be responsible, and must be willing and adequately prepared, for teaching students with ASD. Attitudes are one of the most important predictors for successful inclusion. Teachers indicate a willingness to include students with ASD. However, they do not feel prepared for inclusion for students with ASD. Teacher training and efficacy beliefs are related to teachers' ability to educate students with disabilities. Since teacher training occurs at the preservice teacher preparation stage, it is imperative that we study attitudes and efficacy beliefs of preservice teachers. Researchers have reported positive preservice teachers' attitudes toward inclusion of students with ASD; however, preservice teachers did not feel prepared. Thus, the purposes of this study were to (a) to investigate preservice teachers' attitudes toward inclusion of students with ASD; (b) investigate preservice teachers' efficacy beliefs about their ability to educate children with ASD and disabilities in an inclusive setting; and (c) determine if a combination of special education coursework, preservice teacher experience, preservice teacher gender, and preservice teacher efficacy predict preservice teachers' attitudestowards inclusion of students with ASD. Methods. Preservice teachers from the Midwestern region of the United States (N = 1,028) completed an adapted version of The Opinions Relative to theIntegration of Students with Disabilities (ORI) and The Teachers' Sense of Efficacy Scale (TSES) to measure preservice teachers' attitudes and efficacy beliefs toward inclusion of students with ASD. Results. Results suggest preservice teachers have positive attitudes toward inclusion of students with ASD. However, their efficacy beliefs about their ability to educate students with ASD in an inclusive classroom were low. Preservice teachers had significantly lower efficacy beliefs about their ability to educatestudents with ASD than for their ability to educate students with disabilities in an inclusive classroom. Preservice teachers did not feel prepared for inclusion of students with ASD. Preservice teachers' attitudes toward inclusion of students with ASD were correlated with efficacy beliefs about their ability to educate students with ASD inan inclusive classroom. Teacher efficacy contributed the most to the variance of preservice teachers' attitudes toward inclusion of students with ASD (7.2%). Conclusion. Preservice teachers have positive attitudes toward inclusion of students with ASD, but do not feel prepared for inclusion. They believed they lackthe skill and ability necessary to teach students with ASD. Further, the variables special education coursework, preservice teacher experience with ASD,preservice teacher gender, and preservice teacher efficacy can be eliminated as primary variables influencing preservice teachers' attitudes toward inclusion.