This article investigates the effect of school autonomy on multiple measures of student achievement, combining the individual data of the students participating in the International Civics and Citizenship Survey with their results in the national high stakes standardized tests at the end of eighth grade administered by the Italian National Institute for Educational Evaluation. In general, the results are consistent with previous findings suggesting that the success of decentralization policies in education depends not just on formally granting more autonomy to schools; autonomy can be a prerequisite to laying out a number of institutional (outside the school) and organizational (internal to each school) changes that may lead to the improvement of student achievement.