The study examined concerns, attitudes, and teacher efficacy of 131 in-service, Kindergarten to Grade 8 teachers in three school divisions in Manitoba, Canada. Analyses were conducted to identify the relationships between teachers' back-ground variables, their attitudes and concerns about teaching in inclusive classrooms, and their efficacy for inclusive teaching. In addition, potential effects of training in special education on teachers' concern level were examined. Participants who had undertaken some training in special education had lower degrees of concerns about teaching in inclusive classrooms. We discuss the implications of these findings and how addressing in-service teachers' concerns could enhance their attitudes about inclusive teaching and their overall teacher efficacy.