Self-reported grades are heavily used in research and applied settings because of the importance of grades and the convenience of obtaining self-reports. This study reviews and meta-analytically summarizes the literature on the accuracy of self-reported grades, class ranks, and test scores. Results based on a pairwise sample of 60,926 subjects indicate that self-reported grades are less construct valid than many scholars believe. Furthermore, self-reported grade validity was strongly moderated by actual levels of school performance and cognitive ability. These findings suggest that self-reported grades should be used with caution. Situations in which self-reported grades can be employed more safely are identified, and suggestions for their use in research are discussed. (Contains 3 figures and 4 tables.)