In the last decade regulatory reforms have focused increasingly on efforts to improve regulatory quality. As part of that development policymakers have been encouraged to consider fiscal, socio-economic and administrative effects of proposed legislation when making policy choices. The Central and East European EU member states have adopted regulatory impact analysis (RIA) mechanisms but so far there has been little analysis of their implementation. This article first compares the manner in which RIAs have been institutionalised in the Czech Republic, Estonia, Hungary, Slovakia and Slovenia. Second, it explores how differences in institutionalisation have affected RIA performance. The paper concludes that there are marked differences in the RIA quality across Central and Eastern Europe, notably as a consequence of national differences in institutional and administrative contexts and capacities.