Updated: Oct 2
Poland is part of the Eurozone, but the Euro is not official currency yet. They use zloty.
The zloty is divided into 100 groszy (grosz in singular).
The frequently used Banknotes are 10zł, 20zł, 50zł, 100zł and 200zł.
The commonly used coins are 1gr, 2gr, 5gr, 10gr, 20gr, 50gr, 1zł, 2zł and 5zł.