The Council of Chief State School Officers (CCSSO) was awarded a grant from the National Science Foundation to conduct a meta analysis study with the goal of providing state and local education leaders with scientifically-based evidence regarding the effects of teacher professional development on improving student learning. The analysis focused on completed studies of effects of professional development for K-12 teachers of science and mathematics. The meta analysis results show important cross-study evidence that teacher professional development in mathematics does have significant positive effects on student achievement. The analysis results also confirm the positive relationship to student outcomes of key characteristics of design of professional development programs. The following are appended: (1) Meta Analysis Coding Form Excerpt: Scaffolded Guide for Determining Inclusion of a Document; (2) Effects of Professional Development on Student Achievement, by Study (N = 104); (3) Computation of Effect Sizes, Homogeneity Tests and Q Statistic Analysis; and (4) Correlation Table of Math Post-Only Professional Development Design Elements. (Contains 6 tables and 3 figures.)