The purpose of this study was to explore what Early Childhood Education (ECE) preservice teachers thought about inclusion and what factors influenced their attitude development toward inclusion, based on written reflections collected from 90 undergraduate ECE preservice teachers. Overall, the majority of the preservice teachers believed that inclusion was important and beneficial for both children with and without disabilities. However, some of the preservice teachers described concerns and challenges they might face when working with students with severe disabilities or challenging behaviors. Also, the majority of the preservice teachers reported that direct contacts with individuals with disabilities had a great impact on shaping their attitudes toward inclusion while several preservice teachers indicated that college courses and/or their family members influenced their attitude formation. The implications of the results and suggestions for future research and teacher education programs are discussed.