The purpose of this study was to determine the impact professional development has on student achievement. Specifically, the study was to examine the impact of teachers' professional development activities on student achievement. This was carried out by quantitatively examining the amounts of professional development (number of activities and number of days) and qualitatively examining the types of professional development activities. Metropolitan Nashville Public Schools teachers' professional development questionnaire responses were examined. These responses were analyzed to determine if teachers' professional development activities impact student achievement. A two-way ANOVA was conducted to determine if the number of professional development activities and number of professional development days impact student achievement in mathematics and Reading/Language Arts as measured by TVAAS. A simple linear regression was conducted to determine if teachers' participation in high-quality professional development activities (overall rating) impacts student achievement in Mathematics and Reading/Language Arts as measured by TVAAS. The analysis of data suggested that teachers' participation in high-quality professional development did not impact student achievement in Reading/Language Arts. In addition, teachers' participation in high-quality professional development (overall rating) did not impact student achievement in Mathematics as measured by TVAAS. Further data analysis suggested that the amount of professional development activities did not impact student achievement in Reading/Language Arts. The amount of professional development activities did not impact student achievement in Mathematics as measured by TVAAS. The results of this study indicate that more research needs to be done to examine the impact of teachers' professional development on student achievement. Specifically, studies that are able to investigate whether or not there is a significant relationship between professional development and student achievement need to be conducted. A study is recommended that would examine content specific professional development programs or school district initiatives to determine if they impact achievement in Mathematics or Reading/Language Arts. Other recommended studies should be longitudinal and focus on teachers' professional development and student achievement over 5-10 years. [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.]