The main unit of currency is the zloty (zl), which is divided into 100 groszy (gr). Bills come in denominations of 10zl, 20zl, 50zl, 100zl, and 200zl. The most useful coins are the 5zl, 2zl, and 1zl. You'll also see coins of 50 gr, 10 gr, 2 gr, and rarely 1 gr. At the time of this writing, 1 U.S. dollar was worth around 2.3zl, and 1 British pound about 3.7zl.
Though Poland is a member of the European Union, the country does not use the euro nor are there plans to introduce the euro any time soon. For convenience sake, some hotels will quote their rates in euros and accept euros as payment, but in general it's best to carry local currency.
You can change money in nearly any bank or exchange office, identified in Polish as kantor. You'll see them everywhere, but be sure to shop around for the best rates since they differ from shop to shop. You'll get a decent rate simply by using your credit or debit card in an ATM. In large cities and towns you'll see an ATM on nearly every block.
