This mixed-methods study was designed to compare the achievement in mathematics and reading to that in science since the enactment of No Child Left Behind (NCLB) in 2002. The literature discussed that due to the increased emphasis in mathematics and reading due to NCLB, science education was impacted. Science instruction has endured reduced instructional time, reduced money and resources, reduced test scores on both state and national assessments, and a lack of teacher motivation to teach science effectively. The quantitative portion of the study compared student achievement on state standardized tests in mathematics, reading and science. Student data were obtained from a vocational and technical school within one of Delaware's three counties. The results of the quantitative portion showed a significant increase in performance as students progressed in grade level in both mathematics and reading (p = 0.000) and a significant decrease in performance in science from third to fifth grades (p = 0.000) and a decrease, although not significant, from fifth to eighth grade (p = 0.615) The qualitative portion of the study focused on administrative interviews. Four administrators throughout the county were interviewed to understand their perceptions regarding the impact NCLB has had on science education within their schools. The interviews revealed five concurrent themes regarding the impact of NCLB on science education. The themes included that science instruction has been reduced, money and resources have been reduced, professional development is dominated by improving reading instruction, and teachers feel less motivated to teach science as compared to reading and mathematics. As a result of both the quantitative and qualitative portions of this study, it was concluded that science education has been negatively impacted since NCLB due to the increased emphasis on mathematics and reading instruction. [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]