In about two decades, Spain was transformed from one of the most centralised countries to one of the most decentralised. Spending functions were devolved rapidly. The regions have exercised their discretionary powers quite extensively and innovative policies have been implemented. But devolution was also accompanied by a hike in public employment and pressures on public spending, reflecting duplication in resources and poor co-ordination across and between government levels. The recent devolution of taxing powers could raise the accountability of the regions and, thus, cost-consciousness, although their effective use has been limited. Securing fiscal discipline would require better information on sub-national governments’ policies and outcomes so as to allow citizens to press for improved performance. The financing system of the regions also needs to be reformed to ensure sustainability in the face of changing demographics, while the fiscal rules need to be upgraded to avoid recourse to off-budget operations.