Hi bejay - take a look here http://www.croatiatraveller.com/Money/exchangingmoney.htm

The currency is the KUNA (Kn) ... though some places will take Euros (at their own idea of an exchange rate)! Plenty of ATMS though!

Although the topic is old, there is still no real answer.

The Croatian currency is HRVATSKA KUNA (KN or HRK)

ratio is : 1E ~ 7,5 HRK
1$ ~ 5,5 HRK

Most restaurateurs receives all currencies, It is possible to replace the money in the bank or exchange office

Credit cards are accepted in markets and stores, but not in every restaurant. Watch out for that ! Most restaurants accept euros but for a poor exchange rate. So change the euro at the exchange office, there are many of them in every town or village along the coast.