High-stakes testing is the practice of attaching important consequences to standardized test scores, and it is the engine that drives the No Child Left Behind (NCLB) Act. The rationale for high-stakes testing is that the promise of rewards and the threat of punishments will cause teachers to work more effectively, students to be more motivated, and schools to run more smoothly--all of which will result in greater academic achievement for all students, but especially those from poverty and minority backgrounds. Although it is certainly arguable, the authors believe that, to date, there is no convincing evidence that high-stakes testing has the intended effect of increasing learning. By contrast, there is a growing literature suggesting that the unintended consequences are damaging to the education of students. In this article, the authors offer five reasons--and their thoughts on each--for why high-stakes testing has so easily become a part of contemporary American life.