This study examined the influence of early childhood teachers' beliefs about teaching and self-efficacy beliefs on their self-reported fidelity to a mandated constructivist curriculum. The data were collected from a sample of 308 early childhood teachers from public schools in Turkey. The results of hierarchical regression analyses revealed that early childhood teachers reported a considerably higher level of fidelity to the constructivist curriculum when their beliefs aligned more with the constructivist approach to teaching and had a higher sense of self-efficacy for student engagement and instructional strategies. This impact of teacher beliefs on self-reported fidelity to curriculum implementation was valid regardless of teachers' years of experience, teachers' degree of education, class size, age of the students, length and type of the program, and the existence/nonexistence of a teacher aide in the classroom. Additionally, early childhood teachers' efficacy for instructional strategies moderated the relationship that was found between constructivist beliefs about teaching and self-reported fidelity to learning process. Overall, these findings imply that early childhood teachers' beliefs about teaching and their sense of efficacy in teaching warrant consideration to ensure fidelity to policy documents in educational practice. (C) 2015 Elsevier Inc. All rights reserved.