In 23 states, members of the high school class of 2008 were required to pass a state high school exit examination (HSEE) to earn regular high school diplomas. Proponents of these policies claim that they improve student academic achievement, although critics argue that they reduce the quality of instruction without raising academic achievement. Using nationally representative data collected to facilitate the analysis of temporal achievement trends, the effects of minimum competency and more difficult state HSEEs on student achievement in mathematics and reading between 1971 and 2004 are evaluated. The potential disparate impacts of state HSEEs on the achievement of students by race/ethnicity, socioeconomic status, and prior academic achievement are examined in this study. No evidence is found for any effects of state HSEEs on achievement in either reading or mathematics at the mean or at the 10th, 20th, 80th, or 90th percentiles of the achievement distribution. (Contains 10 notes and 4 tables.)