High-stakes testing pressures schools to raise test scores, but schools respond to pressure in different ways. Some responses produce real, broad increases in learning, but other responses can raise reported test scores without increasing learning. We estimate the effect of an accountability program on reading scores and math scores in Chile. Over a 6-year period, fourth-grade reading and math scores rose by 0.2 to 0.3 standard deviations, on average, and half the rise was due to the accountability program. However, many schools, especially schools serving disadvantaged students, inflated their accountability ratings by having low-performing students miss high-stakes tests. To encourage healthier responses to accountability, we recommend setting accountability goals that are attainable for schools with disadvantaged students, and providing incentives for all students to take high-stakes tests.