Foreign direct investments are widely welcomed and desired source of capital, technical modernisation, employment and improvement of management. There were many advantages attached to foreign inflows at the start of Polish transformation. Initially, firms with foreign investors received tax holidays and other fiscal support. However, it was widely expected that after a certain period of time they gaining profits and paying taxes. Their activity should also support Polish budget by other inflows of indirect taxes.

Unfortunately some foreign investors try to evade taxes and transfers profits or even valuable assets out of the country. On the other hand, high interest rates and possibility of joining the EU tempt to import capital from abroad and invest it on a Polish financial markets - evading capital account restrictions. It all sometimes raises some doubts about the role of the foreign investors played in Polish economy.

The paper tries to estimate, using the methodology proposed by Johnson, Ryan (1994) and Quirk, Evants (1995), the volume of the potential "misinvoiced" inflows and outflows of funds from and to Poland hidden in the trade with the EU countries. The authors try to discuss causes and the scope of this phenomenon in Poland.