The article research problem was to present the theoretical issues and statistics of entrepreneurship in all the rural districts of the Mazowieckie voivodeship. The article was to show the level and concentration of companies’ number in the examined districts. This made it possible to identify the districts with the highest and the lowest level of entrepreneurship as well as the changes in its concentration that took place in the examined period. The research was conducted in 2014, and the main statistical material consisted of the data obtained from the Local Data Bank of the Central Statistical Offi ce. The research outcomes indicate that there was a slight but steady increase of the number concentration of enterprises located in the examined districts in the studied period.