The purpose of this study was to examine the relationship between participation in high school varsity sports and academic achievement and how such relationship may be affected by participating in multiple varsity sports. End-of-course Math and English scaled scores from the California Standards Tests of eleventh-graders along with comparative accumulative grade point averages at the beginning and end of year were gathered and correlated to the number of varsity sports played. The level of sports involvement was categorized by participation in one varsity sport, two varsity sports, or three varsity sports. The differences between males and females were evaluated as well. The hypothesis was that a positive relationship exists between high school varsity sports participation and academic achievement, and such relationship is increased by the number of varsity sports students participate in. The participants in the study were students in five California high schools: Atwater, Buhach Colony, Golden Valley, Livingston, and Merced. The sampling method used was captive and purposive. Pearson Moment correlation was used to determine relationships in the study, and analysis of variance of a single sample was conducted using SPSS. It was found that there was a significant, positive relationship between Math scores and the number of sports played; however, such a relationship was not found between English scores and number of sports played. There was also a significant, positive relationship between accumulative GPA and number of sports played. The benefits of participation were more pronounced for female athletes than for male athletes. Schools and parents can take these results into account when making recommendations to students concerning participation in varsity sports