The validity of assessments, including grading, is paramount to education considering the high stakes decisions and inferences that are made based on grades. This investigation examined the validity of grading practices for middle school teachers in a large, suburban school district in the southeast. In this study, 118 reading and mathematics teachers responded to a survey on best grading practices. Validity coefficients (i.e., correlations) were derived by examining the relationship between student scores on a standardized achievement test and their weighted grade point averages. In reading, teacher validity coefficients ranged from -0.13 to 0.78 with a mean of 0.39 and a standard deviation of 0.20. For math, the range of validity coefficients was 0.24 to 0.89 with a mean of 0.56 and a standard deviation of 0.15. Overall, the validity coefficients for math teachers were higher than those of ELA teachers. The relationship between the validity coefficients and teacher responses to the survey measuring grading practices were then examined by both subject and grade. Items were categorized into five aspects of grading including Behavior, Calculation of Grades, Explanation of Grading Process, Extraneous Variables, and Planning. The frequency distributions of survey responses were also examined. The correlations between validity coefficients and the survey items did not demonstrate a relationship. Although there are many studies and recommendations by measurement specialists regarding grading practices, investigating the validity of grading practices in this manner is not represented in the literature. The results of this study provide initial steps in investigating the relationship between specific grading practices and the quality of classroom grades. [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.]