The purpose of the researcher in this quantitative study was to examine the relationship between principals' leadership practices, school culture, and student achievement as perceived by elementary school teachers. The researcher established the 5 research questions to: (a) determine the differences between high- and low-achievement schools on the 5 variables of leadership practices (model the way, inspire a shared vision, challenge the process, enable others to act, and encourage the heart), (b) determine the differences between high- and low-achieving schools on the 6 variables of school culture (collaborative leadership, teacher collaboration, professional development, collegial support, unity of purpose, and learning partnership), (c) examine the relationship between leadership practices and school culture factors in high-achieving schools, (d) examine the relationship between leadership practices and school culture factors in low-achieving schools, and (e) test whether significant correlations exist between leadership practices and school culture factors in high- and low-achieving schools. The instruments used in this study were the Leadership Practices Inventory-Observer, the School Culture Survey, and a demographic survey. The sample included 154 elementary school teachers in 6 high-achieving schools and 6 low-achieving schools in a single Texas Region 10 independent school district. The researcher used both a descriptive-comparative research design and a correlational research design. Participants responded anonymously to 72 survey questions via an electronic survey. The researcher tested 5 hypotheses and examined 5 research questions. Independent-samples t tests and Pearson correlations were used to test hypotheses. The Statistical Package for the Social Sciences (SPSSRTM) version 22.0 was used to calculate t tests and Pearson correlations. The t test analysis revealed no significant differences existed in the 5 leadership practices between the principals in high-achieving schools as compared to principals in low-achieving school. The t test analysis also revealed no significant differences in the 6 school culture practices between principals in high-achieving schools as compared to principals in low-achieving schools. Pearson correlations demonstrated that a statistically significant relationship existed between the 5 leadership practices and six school culture factors in both the high-achieving subsample and low-achieving subsample. The correlation coefficients between the 6 school culture variables and the five leadership practices were significant in both the high-achieving subsample and low-achieving subsample. The findings of the study are important to educational leadership programs and principals in both high- and low-achieving schools. The findings add to the empirical literature on the theories of effective school culture and leadership factors in schools at the organizational level to improve student achievement. Implications and recommendations for school practices and future research are discussed. [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.]