The main goals of audit of local and regional self-government units are to verify the authenticity and credibility of the financial statements, examine the compliance of operations with acts and other regulations, analyse the realisation of revenues, receipts, costs and expenditures in accordance with the plan, as well as other goals. After performance of the audit, reports are drawn up, which are available to the public. The aim of this study is to determine the realisation of tax revenues in total revenues and receipts of local units, based on data obtained by the audit procedures. The main role of local and regional self-government units is satisfying public needs, as well as improving living and working conditions in a particular area. Through the process of decentralisation, ie by transferring of tasks to be provided by individual levels of government, the local interests and demands for public goods and services can be satisfied in the best possible way. It is therefore necessary to collect budgetary revenues and ensure sources of funding for performance of tasks that fall under the competence of local units. The realisation of tax revenues needs to be analysed by individual types and by counties, for a specified period. The study covers the period from 2007 to 2011, and the fiscal capacity of the counties is presented by analysing the revenues and receipts in relation to the number of inhabitants for each unit of local (regional) self-government.