As a result of poor student performance, professional development has emerged as a key strategy for improving instruction and achievement. In times of reduced resources and increased accountability, schools must evaluate their efforts in order to make sound decisions about policy and practice. This mixed method study was designed to investigate professional development evaluation practices and whether a relationship exists between professional development evaluation and math achievement in two groups of middle schools in one county school district. One group of middle schools met state standards in mathematics and the other group of schools did not meet state standards. The study sought to assess the perceptions of middle school principals, staff development teachers, and district level staff development instructional specialists/directors regarding the five levels of professional development evaluation: participant reactions, participant learning, organization support and change, participants' use of new knowledge and skills, and impact on student learning outcomes. According to Guskey (2002), the levels of evaluation are sequential and hierarchical and in order to increase the chance for successful impact on student achievement, all levels must be carefully considered in planning professional development experiences for teachers. These data were gathered through the use of a survey and focus group interviews . A survey instrument was designed to solicit perceptions of the levels of professional development evaluation in schools. There was no statistically significant difference between principals and staff development teachers in the schools that met state standards in mathematics and those who did not. The researcher conducted a one way analysis of variance of differences between the perceptions of professional development evaluation practices of principals, staff development teachers, and instructional specialists/directors in both met and non-met schools. Focus groups were held with principals, staff development teachers, and staff development instructional specialists/directors to identify the types and levels of professional development evaluation across middle schools. This study has training, policy and practice implications for middle school principals and staff development teachers as they implement professional development evaluation efforts aimed at improving middle school mathematics. It is expected that this research will assist school systems in their school improvement efforts. [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.]