The impact of regulation on productivity is an issue that has attracted increasing interest in recent decades, as some scholars have argued that the proliferation of red tape may be the cause of slower growth rates in some western economies. Regulation (and other public instruments) has significant effects that may be either benign or harmful. Justified and well designed regulation protects consumers from potentially unsafe products, limits pollution, enhances workplace safety and contributes to public health and safety, as well as a more productive and fair society. However, an overabundance of rules or badly designed regulation can cause confusion and delay, impose unreasonable compliance costs in terms of capital investment, labour and official paperwork, retard innovation, lower productivity and, accidentally, distort incentives for private initiative. The objective of this paper is to examine the possible impact of regulatory activity in the Spanish regions over the past decade (1989–2001) on growth and productivity.