In recent years, many states have passed laws requiring dyslexia training for teachers. Research suggests teachers hold both scientifically-based conceptions as well as misconceptions of dyslexia, but there is little research regarding the specific concepts of dyslexia in which teachers are unsure. Research on conceptual change suggests a different teaching approach is needed if an individual holds a misconception rather than an uncertainty. The purpose of this study was to examine the concepts of dyslexia teachers know accurately as scientific conceptions, hold as misconceptions, or are uncertain. We also examined if other factors, including teachers' (a) amount of previous training, (b) years of experience, or (c) confidence predicted their knowledge of dyslexia. Teachers (n = 524) from a Midwestern state with recent legislation requiring dyslexia training for teachers and evidence-based structured literacy instruction for individuals with dyslexia participated in this study. The Dyslexia Knowledge Questionnaire-2 was administered, which includes 37 Likert scale items regarding dyslexia informed by conceptual change theory. Results indicated a complicated conceptualization of dyslexia. For some concepts, teachers either mostly held scientific conceptions or held misconceptions. For other concepts, teachers were either distributed between scientific conceptions, misconceptions, and/or unsure or responded differently depending upon whether the item contained a term versus an explanation of the term within the item. Although teachers' amount of previous training and confidence did significantly predict dyslexia knowledge, years of experience did not. Implications for teacher training in dyslexia are discussed.