In the current study, the authors qualitatively investigate, through the theoretical perspective of cognitive dissonance, the relationship between teacher beliefs and their associated teacher practices at two public elementary schools with diverse student populations. They argue that while teachers may hold theoretical beliefs about culturally proficient teaching, they may also hold deficit beliefs associated with pre-existing cognitions about the reasons for disparities in the academic outcomes of diverse student populations. Three research questions guided this study: (1) What beliefs (culturally proficient beliefs, deficit beliefs) do teachers hold about teaching students from diverse populations; (2) What are the classroom practices of teachers with diverse students; and (3) What is the relationship among culturally proficient beliefs, deficit beliefs, and teacher practices in the classroom? The authors present and discuss the findings in light of the relevant literature and cognitive dissonance theory. The study concludes with several recommendations for teacher practice and future research.