The purpose of this action research study was to conduct a professional development activity to provide content-area teachers with academic vocabulary strategies to be implemented during instruction on a daily basis. Professional development is essential for teachers to gain new knowledge and skills in order to hone their craft to improve student learning. Teachers at a middle school in southeastern United States were unsure how to integrate academic vocabulary strategies during daily instruction. The student population was approximately 960, and approximately 50% struggling learners functioning below grade level in vocabulary knowledge. The target population of the study was 11 middle school content area teachers who had been working at the research site for at least three years. Kirkpatrick and Kirkpatrick (2007), Implementing the four levels: A practical guide for effective evaluation of training programs model served as the theoretical framework for this study. Qualitative data were collected from the study participants in the form of questionnaires and an assessment and used for analysis. The study sought to determine how and to what extent teachers reported self-assessed change in their perspectives following professional development, and how and to what extent the implementation of academic vocabulary strategies had an impact on teachers' on-the-job behaviors. Kirkpatrick and Kirkpatrick (2007) research supported that there must be a change in perspectives and on-the-job behaviors to demonstrate that learning had occurred. The instrument used to gather the qualitative data in this study was adapted from previously used Kirkpatrick's surveys. Creswell's (2005) (Educational Research: Planning, conducting, and evaluating quantitative and qualitative research) qualitative data analysis process was used to determine the thematic codes for this research study. This study demonstrated that as a result of the professional development activity, teachers were able to report a self-assessed positive change in perspectives and on-the-job behaviors in teaching academic vocabulary in content. [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/en-US/products/dissertations/individuals.shtml.]