There is a need for intervention programs that support teenagers' social and emotional development in American public schools. Education stakeholders have observed a disproportionate decline in social-emotional skills among minority and at-risk adolescents in low performing schools, increasing dropout rates and early exposure to the criminal justice system. The purpose of this basic qualitative study was to explore the inconsistent application of social-emotional learning (SEL) by high school teachers in a local Southeast regional school district. Semistructured interviews were conducted with 10 English language arts high school teachers to obtain their perspectives on instructional implementation of SEL curriculum using the Collaborative for Academic, Social, and Emotional Learning (CASEL) framework, the consistency with which they employ SEL practices, and the influence of SEL on student outcomes. The CASEL, designed by a foundation with the same name, was the conceptual framework for this study. Data were analyzed using a priori and in vivo codes, revealing six themes: (a) teachers' perceptions, mindsets, and biases drive pedagogy; (b) consistent and continuous training is needed to build teachers social-emotional competence (SEC); (c) SEL instructional planning is key to successful implementation; (d) knowledge and use of SEL strategies are inconsistent and minimal; (e) barriers to SEL impede successful program implementation; and (f) teachers struggle to assess SEC in their students. The study can promote social change by providing policymakers with strategies to increase youths' psychological and physiological well-being and supports using SEL to address the diverse needs of at-risk adolescents and propel students toward academic and life success. [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.]