The only legal tender in Ukraine today is hryvnia (UAH) which equales to one hundred kopiykas. Hryvnia has apeared on the 2nd of September, 1996. There are bills for 1, 2, 5, 10, 20, 50 and 100, 200, 500 s. Coins are for 1, 2, 5, 10, 25 and 50 kopiykas.
Hryvnia can be easily converted to any other currency in any authorized bank of Ukraine or in numerous currency exchange offices. Please note that they do not exchange coins in Ukraine, so only banknotes are convertible.
You can withdraw money by numerous cash dispensers (ATMs) too. In Ukraine an ATM will give you money in hryvnias. Note, that Ukrainian keypads have no letters, so in order to withdraw money from ATMs PIN must contain numbers only. One will pay a fee for using ATMs but this fee is considerably lower than that for traveler's checks.