Teachers encountered difficulties implementing 90% of Target Language (TL) use and tried various strategies to promote it. This qualitative case study investigated secondary foreign language teachers' perceptions and experiences of following the district's recommendation to use 90% and above of TL in their classrooms in a school district in the Midwestern region of the United States. Surveys were sent to all secondary foreign language teachers in the district to collect background information and perceptions of TL use in the classroom. Four participants were selected for a semi-structured interview for a deeper understanding of their perceptions and experiences of TL use. Five common themes are revealed by both inductive and deductive coding: 1) there is a disparity between recommendation and reality, which means that teachers think 90% of TL use is ideal but challenging to achieve; 2) students lack real motivation to learn a foreign language; 3) various levels of language proficiency exist among students, some students' low proficiency level makes it difficult to implement 90% TL; 4) teachers use L1 to check for understanding, and 5) teachers use modeling to promote TL. Additionally, inductive coding reveals six other themes that are unique to this study: 1) students are reluctant to try to use TL; 2) lack of support from the district, schools, and parents; 3) teachers offer students tools and resources to learn; 4) teachers open to new ideas and want program-specific training; 5) teachers use project-based learning to promote TL use, and 6) teachers use partner and small group work to promote TL use. It is hoped that this study contributes to making the district, schools, and community at large aware of teachers' perceptions and needs so they can support them in providing students with a more effective and better foreign language experience by maintaining the use of the TL in the classroom as much as possible. [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.]