This study examined student grades in correlation to Georgia's high-stakes testing—end-of-course tests (EOCTs) and Georgia High School Graduation Tests (GHSGTs)—in three high schools in northwest Georgia. Although there are many studies on the topics of student achievement and high-stakes testing, few of these studies report about the relationship between student grades and high-stakes testing. Research has implied that student grades incorrectly inform about student achievement. This study was an attempt to conclude if there was a relationship between student grades and the results of high-stakes testing, focusing on courses in which an EOCT was assigned and that also had a corresponding GHSGT. The mean course grades in American Literature and U.S. History for three high school student groups were compared using a one-way analysis of covariance. The students consisted of high school juniors who completed an assigned EOCT and were first-time test takers for a corresponding GHSGT. The convenience sampling utilized resulted in a total of 819 students in U.S. History and 811 students in American Literature. The associated GHSGTs were used as the covariate between the testing groups. The test results of between subjects indicated a statistically significant difference ( p ≤ .05) in student grades in U.S. History, p = .001, and a statistically significant difference (p ≤ .05) in student grades in American Literature, p = .001. The findings are significant in their examination of teacher grading practices, assessment for learning, and real versus perceived student achievement. Research results further indicate a need for additional studies into the attitudes of all educational stakeholders regarding the inclusion of high-stakes testing results in student grades.