The purpose of this article is to describe what has been learned over the past 20 years of research on general early childhood preservice teachers' attitudes toward inclusion. An extensive literature review was conducted to critically examine the purposes that guided the reviewed studies, the methods used to measure preservice teachers' attitudes toward inclusion, and the major findings of these studies. A total of sixteen studies were identified. Results of this review revealed that general early childhood preservice teachers held positive attitudes toward inclusion. However, they had mixed feelings toward their preparedness for working with children with disabilities, especially those children with severe disabilities or challenging behaviors. Related to factors (e.g., course work, field experience) that influenced the teachers' attitudes, there were mixed findings. The methods the researchers used varied, although most studies included surveys or interviews. Gaps in the literature and implications for future research and practice are discussed.