The purpose of this study was to examine the relationship between pre-service teachers' physics epistemological beliefs and their knowledge of physics and pedagogical knowledge. The participants were pre-service physics teachers studying in a state university. Both qualitative and quantitative research methods were carried out to collect and analyze the data. Epistemological Beliefs Questionnaire for Physics Science developed by the researchers was used in semi-structured interviews. The questionnaire contained 17 open-ended questions distributed to the following five non-orthogonal dimensions: Structure of Scientific Knowledge, Nature of Knowing and Learning, Real-Life Applicability, Evolving Knowledge, and Source of Ability to Learn. In order to look for a relationship between the participants' epistemological beliefs and their knowledge, comparisons were made between the participants' epistemological beliefs in each dimension and their GPA (Grade Point Average) scores of physics courses, physics education courses and education courses. Scores were assigned to the levels of epistemological beliefs and GPA scores to examine patterns. Non-parametric Spearman-Rho analysis was performed to search for a statistical correlation. The following conclusions can be drawn from the study: First, pre-service physics teachers do not have the highest level epistemological beliefs in the domain of physics which are necessary for conceptual change, understanding nature of science, and engaging in scientific inquiry process. Hence, this study suggests that science and science education programs need to be enhanced to facilitate students' epistemological beliefs in the specific domains. Second, pre-service teachers' physics knowledge is related with their beliefs about real-life applicability, nature of knowing and learning, and source of ability to learn. Therefore, physics needs to be thought by facilitating construction of one's own understanding with the help of working through the material actively, relating new material to prior experiences, intuitions, and knowledge, and reflecting upon and monitoring one's understanding. Additionally, students need to relate science to real world applications during the courses. Third, pre-service physics teachers' pedagogical content knowledge is associated with their physics related epistemological beliefs. As a result, improvement in beliefs may cause improvement in pedagogical content knowledge.