Teachers' beliefs about knowledge in their subject deeply impact their classroom practice. This study analyzed the epistemic beliefs about physics knowledge held by Saskatchewan high school physics teachers using a newly designed framework of epistemic beliefs about physics knowledge. Results suggest that teachers' epistemic beliefs about physics knowledge are relatively consistent within the areas of certainty and structure of physics knowledge; most participants believed that physics knowledge was tentative and subject to change as well as coherent and connected in its structure. However, participants rarely agreed on the source and content of physics knowledge. As teachers' beliefs likely influence the way a curriculum document is interpreted and implemented, students across the province of Saskatchewan might develop very different understandings of physics knowledge due to variations in teachers' epistemic beliefs. The findings of this study provide insights into areas of professional development for teachers and pre-service teacher instruction. The article concludes with suggestions for educating teachers to better understand their own epistemic beliefs about knowledge in the subjects they teach as well as the impact these beliefs may have on their classroom.