The No Child Left Behind Act of 2001 has challenged educational leaders to develop effective strategies to increase the academic achievement of all learners. At the center of this reform effort is the school principal. This study explored the relationship between creating professional learning communities in public high schools and increasing the level of student achievement. The purpose of this study was to measure, compare, and contrast the perceptions of high school principals regarding the degree to which their school had developed learning communities based on Senge's 5 disciplines. Descriptive and ex post facto research was conducted to gather quantitative data through the use of the Learning Organization Survey. A sample of 100 high school principals was used to develop an equal-sized, stratified, random sample based on student performance of the High School Proficiency Assessment. An independent t-test was used to test for statistical significance between the mean scores of high- and low-achieving schools. A two-sided test of significance was used at the .05 level to determine the confidence interval for the sample population. Results indicated a statistically significant difference on 36 out of the 40 questions surveyed. These results further indicated a significant difference between high- and low-achieving principals regarding the disciplines of personal mastery, mental models, shared vision, team learning, and systems thinking. This study describes how to integrate these findings into a strategic plan for principals to establish learning communities based on Senge's 5 disciplines. This research study contributes to social change by providing principals with possible strategies for increasing the achievement levels of all students.