ABSTRACT OF THE DISSERTATION OF Yahya Assiri, for the Doctor of Philosophy degree in Curriculum and Instruction, presented on August 19th, 2016, at Southern Illinois University Carbondale. TITLE: SCIENCE TEACHERS’ KNOWLEDGE, BELIEFS, VALUES, AND CONCERNS OF TEACHING THROUGH INQUIRY MAJOR PROFESSOR: Dr. D. John McIntyre, Professor Emeritus of Curriculum and Instruction, Ed.D., Southern Illinois University Carbondale, Department of Curriculum and Instruction. This study investigated elementary science teachers’ knowledge, beliefs, values, and concerns of teaching through inquiry. A mixed-methods research design was utilized to address the research questions. Since this study was designed as a mixed-methods research approach, the researcher gathered two type of data: quantitative and qualitative. The study was conducted in Mohayel School District, Saudi Arabia. The information was collected from 51 participants using a questionnaire with multiple choice questions; also, 11 participants were interviewed. After collecting the data, descriptive and comparative approaches were used. In addition, themes and codes were used to obtain the results. The results indicated that the mean of elementary science teachers’ knowledge was 51.23%, which was less than 60% which was the acceptable score. Also, the qualitative results showed that science teachers had a limited background of teaching through inquiry. In addition, the elementary science teachers had a high level of belief to teach science through inquiry since the mean was 3.99 out of 5.00. These quantitative results were confirmed by the qualitative data. Moreover, the overall mean of elementary science teachers was 4.01, which indicated that they believed in the importance of teaching science through inquiry which was also confirmed by the responses of teachers in the interviews. Also, the findings indicated that elementary school science teachers had concerns about teaching science through inquiry since the overall mean was 3.53. In addition, the interviewees mentioned that they faced some obstacles when they teach by inquiry, such as time, resources, class size, and the teachers’ background. Generally, the results did not show any significant differences among elementary science teachers’ knowledge, beliefs, values, and concerns depending on gender, level of education, and teaching experience. However, the findings indicated there was one significant difference which was the level of teaching experience between groups: (6-10) years and (11-15) years, and (16- more) and (11-15) years. In addition, the implications and suggestions for future research were provided to enhance teaching science through inquiry.