Georgia adopted science standards encouraging teachers to use inquiry-based instruction in science instruction in 2016 to improve science exam scores. The problem was a lack of improvement in science exam scores in middle school and high school students in a small rural school district in South Georgia since inquiry-based standards have been put in place. There is a gap in the literature examining teacher perceptions and experiences of inquiry and mixed-method instruction with improving science exam scores. The purpose of the exploratory case study was to explore science teacher perceptions of the lack of science exam improvement in middle and high school student performance. Two research questions were developed to explore the perceptions of science teachers with inquiry and mixed-method instruction regarding improving student performance and the experiences using inquiry and mixed-method instruction improving student performance. Experiential learning theory and constructivist theory were the guiding theoretical frameworks of this qualitative study. Semi-structured interviews via Zoom were used to collect data from a purposive sample of 16 middle and high school science teachers with at least 1 year of experience teaching science. Thematic analysis was conducted to analyze the interview transcripts for emerging themes. Participants shared challenges of teaching through inquiry such as student motivation and a lack of math and reading skills. Participants also shared the perception that mixed-method better meets the needs of students with varying academic achievement. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]