A number of studies have dealt with the effects of economic integration on foreign direct investment, however without a comprehensive and simultaneous analysis of the overall positioning of these countries along the investment development path (IDP). In the current paper, a comparative analysis is conducted of IDPs of four Eastern European countries, both members and non-members of the European Union. The purpose of the paper is to determine the effect of economic integration on foreign direct investment (FDI) flows and on the movement of these Eastern European economies through their IDP stages.