Teachers in a New Jersey suburban high school noticed an increase in students' stress and anxiety associated with high-stakes testing, and they were struggling to find strategies and interventions to help. The purpose of this study was to investigate high school English and mathematics teachers' current knowledge, experiences, and perceptions about students' preparation and responses to high-stakes testing and to explore teachers' perceptions about teaching strategies they needed to reduce student test anxiety. Liebert and Morris's bidimensional components of anxiety, emotionality, and worry form the conceptual framework that guided this study. The research questions focused on teachers' perceptions about students' high-stakes testing readiness, students' testing behaviors, and teachers' training needs. A case study design was used to capture the insights of 12 high school English and math teachers through semistructured interviews and a focus group interview; a purposeful sampling process was used to select the participants. Emergent themes were identified through open coding, and the findings were developed and checked for trustworthiness through member checking, rich descriptions, and researcher reflexivity. The findings revealed that teachers recognize that students react in different ways to testing, that students who are prepared for the tests demonstrate greater confidence and less anxiety, and that teachers want more professional development specific to reducing students' anxiety and stress. A professional development project was created to provide teachers with strategies and approaches to prepare students for high-stress testing situations. This study has implications for positive social change by creating a structure to provide teachers with strategies for managing students' test anxiety.