This study illustrates the macroeconomic situation of Poland before and after its accession to the European Union in 2004. It focuses on the inflow of foreign capital and its influence on the development of the country's economy. The first part of the study focuses on the term foreign direct investment as well as the general information about the country. The following part gives an impression about the situation before Poland became a member of the European Union. Furthermore an insight is given into the amount of foreign capital inflow to the country and the nationalities of foreign investors. In addition to that, the study shows to which industries most of foreign investment has been assigned to. The positive effects of foreign direct investment arose mainly in the sectors of infrastructure, technology transfer and education. Additional improvement should be pursued in areas such as the treatment of the environment and the combat of the high unemployment rate. This study is addressed to readers with interest in politics - especially the European Union, the economic development of Poland as well as the country as such.