currency

always use the local currency

Czech Krona. Merchants that accept Euros would charge you a premium in Euros.

Can you use euros? Sometimes. It's similar to using US dollars in Canada. But, just like in that situation:

1) No one is obligated to accept euros - it's at their option. I further encountered places that would accept euro bills, but not euro coins.
2) They exchange rate at which they accept euros is up to them to set. It may be close to fair, or may be a total rip-off.
3) Any change you get will be in Czech koruni.

So, unless you're just passing through, definitely get Czech koruni from ATM's, or use your credit card and make sure the charge is processed in koruni rather than any other currency.

use euros in exactly the same way as you would at home.

Unclegus, you win, hand down. That is the best response ever to age-old "what currency should I use in _____?"

Actually in some businesses in C.R. you can use Euro but always to your disadvantage. Smart people use Czech koruna (crown).

If an establishment in the CR allows me to pay in Euro and I do that, I am not going to quibble over the change since they accepted my Euro in the place.

Fred: I never said you, or anyone else, would or should quibble over this. But I've seen people who weren't prepared get very irate.

And yes, using euros in Prague isn't like trying to use euros in Canada; it's like trying to use US dollars in Canada. Sometimes they will "work," but it's not the best way to go, for all the reasons stated above.

@ Harold...Maybe "quibble" is inexact, what I mean is that after paying in Euro in an amount closest to Czech Krone, I would not be concerned about the change since they allowed me the luxury of paying in Euro, eg, if the amount were 8.50 Krone, and I handed over a ten Euro bill, let alone nine Euro in coins. I am not concerned about the change.

when you withdraw money from an ATM in Prague .... I imagine you receive crowns not euros -- is this correct? thanks

Yes, in using the ATM in Prague, you will receive Czech currency, not Euro.

Maybe not so much anymore, but it might not be unusual for a smaller B&B or some hotels to quote a cash price in euros and expect payment in euros, in that case, using euros is fine if you are agreeable to the price. But for everything else, use local currency.