Purpose, scope, and method of study. The purpose of this study was to determine if and to what degree a relationship existed between physical fitness and the academic achievement of ninth-grade public school students in Arkansas. A sample of 152 students from four different schools participated in the study. The dependent variable was academic achievement as measured by the Stanford Achievement Test, 10th edition (SAT 10). Scores were obtained for both reading and math. The main predictor variable was physical fitness as measured by the Fitnessgram criterion-referenced evaluation. Other predictor variables included were gender, ethnicity, and socioeconomic status. A partial correlational analysis was performed to determine whether a relationship existed between the level of physical fitness and academic achievement. Two separate stepwise multiple regression analyses were performed to determine the best combination of predictors for both reading scores and math scores. Findings and conclusions. Analyses were performed in response to four research questions. Results of the analysis for Question 1 revealed no relationship between the physical fitness score and SAT 10 reading scores when controlling for the other predictor variables. Results of the analysis for Question 2 indicated a positive relationship between the physical fitness score and SAT 10 math scores when controlling for the other predictor variables. Results of the analysis for Question 3 indicated that the best predictor of SAT 10 reading scores was socioeconomic status. The analysis for Question 4 resulted in an optimal prediction equation for SAT 10 math scores, which consisted of the variables socioeconomic status and physical fitness score. [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.]