The volume of international trade and the share of foreign capital in companies as well as their dynamics in 2005 and 2010 have been analysed. It enabled a verification of the hypotheses on changes, forms and levels of internationalisation. The process of internationalisation depends on the size of the company as well as on its location. There are two important determinants of internationalisation: potential and agglomeration effect. They are responsible for the differentiation of internationalisation of companies in rural and urban areas.