On 4 December 2016, a large majority of Italian voters turned down the most comprehensive and cohesive attempt to revise significant parts of the Constitution since 1948, namely, to overcome the country’s symmetrical bicameralism, to establish new state-region relations, and to streamline institutions, in part by abolishing the provinces and the National Council for Economics and Labor. This chapter offers an outline of the reform, which had been boldly approved by Parliament, and places it within its political and institutional context. It identifies the changes that the reform was set to introduce, attempts to assess the effects it would have had if it had been passed in the referendum, and considers some of the consequences of its rejection.