The external audit of financial reports concerned with Spanish Regional Governments is characterized by a high degree of heterogeneity. The scope of the reports, their content and their structure present significant differences. In some regions, the audit reports are issued by regional audit institutions, while in others, that have not yet developed those audit regional bodies, reports are approved and issued by the Central Government Audit Supreme Court of Accounts .This paper pursues a double purpose. On the one hand, to classify Spanish Regional Governments according to the development of their auditing systems, taking into account the scope and content of the reports issued by the different audit institutions. On the other hand, the aim to establish a relationship between (a) the degree of development of the different external audit systems and (b) the financial position of each region and their degree of compliance with budgetary stability rules.