This study examined the beliefs of in-service teachers working in inclusive classrooms regarding developmentally appropriate practices and how those beliefs affected their attitudes toward, knowledge of, and comfort levels regarding working with children with disabilities. A mixed-method approach was utilized and data were collected through the use of three survey instruments: Teacher Belief Scale and Instructional Activities Scale (Hart et al., 1990) and the In-service Teacher Self-Report Survey (Mitchell, 2002). Data were also collected through open-ended questions to assess Teachers' perceived level of preparation for the inclusive classroom. This study also examined whether education or experience levels had an influence on teachers' perceptions regarding inclusive practices. Results of the study indicate that there is not a significant relationship between in-service teachers' beliefs regarding developmentally appropriate practices and their attitudes toward, knowledge of, and comfort levels regarding inclusion. Additionally, results indicate that the teachers' levels of education or experience do not necessarily indicate that they are prepared to meet the needs of the inclusive classroom environment. Implications regarding the preparation of and ongoing training needs of teachers are discussed. (Contains 6 tables and 1 figure.)