This study examined the extent to which end-of-course grades are predictive of Virginia Standards of Learning test scores in nine high school content areas. It also analyzed the impact of the variables school cluster attended, gender, ethnicity, disability status, Limited English Proficiency status, and socioeconomic status on the relationship between end-of-course grades and SOL test scores. Data for this quantitative, correlational study was obtained from a large public school district in Virginia. Research findings include a moderate to high correlation between grades and SOL scores, and the strength of the relationship was dependent on content area. All math content areas and two of three science content areas demonstrated a substantial to high relationship between grades and test scores, while one science and all three social studies content areas analyzed demonstrated a moderate relationship. Furthermore, all variables studied, including school cluster attended, gender, ethnicity, disability status, Limited English Proficiency status, and socioeconomic status, significantly impacted the relationship between end-of-course grades and SOL test scores. The most notable impacts were between disability status and Limited English Proficiency status, as students with disabilities and students of limited English proficiency were associated with lower test scores. Also notable was the impact of gender on test scores, as male students were associated with higher test scores.